Whenever asking for help, please include your Operating System and/or Distribution.  (platform in the bugheader)  I have no idea if Woob is available on Windows or MacOS.  Also, the website component is used for bugs in the KMyMoney website.  I've adjusted to importer.
Unfortunately, the handbook is known to be out of date.  I am actually working on a complete review and  update, but that has just begun, and will not likely be available until the eventual release of 5.2.  
For instructions, have you looked at the woob web site at all?  The site referenced in the doc is correct https://woob.tech.  It is just the particular page which has changed or removed.
The woob plugin for KMyMoney was added by a developer who is no longer actively participating with the project, and I don't believe anyone else on the team has actually used it.
My best advice for now is to be sure you have woob set up and functional from command line for use with your bank.
The woob plugin is activated at runtime only if woob is found on your system.  If it is installed and not found, there might be some hint of why it can't find it in the console output.

ok, the platform is Windows 11, kmymoney Version 5.1.3.

woob is installed on my system ( on windows thats possible via pip.exe as described on the woob website ).
Still kMyMoney does not show any option or interface or menu for using the woob interface, at least i have not found one. 

The reason I want to use woob is that HBCI does not work for any of my banks (and the aqbanking appears to be just another mostly undocumented or not working feature of kmymoney).

aqbanking works just fine, as far as I know, but I don't use it as I'm in the US, and ofx is the best the banks here offer.  I would have to hunt for it, but aqbanking documentation should exist outside of KMM.  
woob SHOULD be found by KMM if it is installed, although I suppose it is possible it is getting confused about the location.
The next thing to do is invoke the Settings/Configure KMyMoney... menu item, select the Plugins item on the left side, and find the entry for woob.  If it is present, there might be a checkbox to enable it.  However, I suspect it will not be there, indicating KMM did not find it.  
In that case, you need to start KMyMoney from console.  I have no access to a Win11 system, so I don't know the terminology, but you need to bring up a terminal or console (it used to be CMD.)  Then just enter "kmymoney" and hit enter.  If that complains about it not being found, you need to enter the full path to the kmymoney.exe file.  When you do that, there will be lots of output to the console.  You will need to hunt through that to find any messages about woob.  It should say where it looked for the plugin.  Post the relevant lines here, and also where woob is actually installed, and we'll figure out how to make KMM find it.

Created attachment 161183 [details]
associate an account to woob

Woob should be available by right clicking on your account, then click on "associate an account"

(In reply to antoine from comment #4)
> Created attachment 161183 [details]
> associate an account to woob
> 
> Woob should be available by right clicking on your account, then click on
> "associate an account"

Thanks for the hint. However, there is no option for woob present in the Map Account menu.

(In reply to Jack from comment #3)
> aqbanking works just fine, as far as I know, but I don't use it as I'm in
> the US, and ofx is the best the banks here offer.  I would have to hunt for
> it, but aqbanking documentation should exist outside of KMM.  
> woob SHOULD be found by KMM if it is installed, although I suppose it is
> possible it is getting confused about the location.
> The next thing to do is invoke the Settings/Configure KMyMoney... menu item,
> select the Plugins item on the left side, and find the entry for woob.  If
> it is present, there might be a checkbox to enable it.  However, I suspect
> it will not be there, indicating KMM did not find it.  
> In that case, you need to start KMyMoney from console.  I have no access to
> a Win11 system, so I don't know the terminology, but you need to bring up a
> terminal or console (it used to be CMD.)  Then just enter "kmymoney" and hit
> enter.  If that complains about it not being found, you need to enter the
> full path to the kmymoney.exe file.  When you do that, there will be lots of
> output to the console.  You will need to hunt through that to find any
> messages about woob.  It should say where it looked for the plugin.  Post
> the relevant lines here, and also where woob is actually installed, and
> we'll figure out how to make KMM find it.

(In reply to KB.claim from comment #0)
> Website
> https://docs.kde.org/trunk5/en/kmymoney/kmymoney/details.impexp.woob.html is
> very unspecific about how to use woob in kmymoney. 
> 
> How can one get to woob in kmymoney? Via import menu? No idea how to use
> woob even when it is installed.
> 
> Additionally the link to the "Woob website" is not working (Please refer to
> the instructions on Woob website.)
> 
> The kmymoney documentation sadly is very very unspecific and as vague as the
> description for woob.

for aqbanking: two aspects to consider 1) the module does not work for me - i am still testing, but it seems in kmymoney most things are not that trivial to achieve. Alone to get the aqbanking running was not easy. However, it runs now, but did not succeed so far to establish a connection. 2) availablity of HBCI - sadly most of my banks do not provide a HBCI interface (anymore). Many go to PST2 (or so) which requires getting a license and registration and i understood that as nothing for end users but for commercial software product makers.

for woob: starting via the command line did not bring up any usable message relating to woob. woob is installed and the woob bank module runs. So this should be enough for kmymoney to detect this module (if it searches for it, which is how the comments sounded). However, there is no module in the configuration (settings dialogue) or so. Also mapping an account to a datasource does not give woob as an option. I wanted to try the woob on a ubuntu installation, but same there. woob is installed, the banking module works, but it does not show up anywhere in kmymoney. 

I am not specifically looking for woob, but a method to import data from all my online banks into kmymoney to avoid typing in the transactions. This is not really working .... at least for european banks and sadly the description is almost non existant. kbanking, aqbanking, woob ...

None of the online banking methods will work if the bank does not support it.  Can you confirm that your bank supports the method you are trying to use?

For further help with aqbanking, please use one of the venues suggested in https://kmymoney.org/support.html.  I don't use aqbanking, but there are others who do, and can probably help figure out what you are missing (assuming your bank does support it.)

If the console output did not mention anything at all about looking for woob, then we need to confirm that the plugin was actually compiled into the version you are using.   Can you say where you downloaded it?  I will try to dig into the version provided at kmymoney.org and confirm it does support woob.

In terms of a practical solution, you probably need what is called Web Connect.  Log into your bank's web site and view the account.  There should be a button or link for Download.  You would need to specify the time period.   Some banks allow custom date ranges, others restrict you to statement periods or "current" which is transactions since the last statement.  You will then need to select the format of the download.  If they offer a download for Quicken, that is the best to use.  Initially, save the downloaded file somewhere, and then in KMyMoney select the File/Import/OFX menu item and select that file.  If that works, you should be able to configure your browser to associate that file (usually ending in .qfx, but possibly .ofx) with KMyMoney, so when you download a file of that type, the browser invokes KMyMoney, which will then import it.  The first time you do this, you will need to tell KMyMoney which account to use, but it should remember that for further use.

Said console output looks something like this (I don't have woob itself installed and that may cause some of the failures reported):

:
:
Loading "/usr/lib64/qt5/plugins/kmymoney_plugins/sqlstorage.so"
Plugins: sqlstorage loaded
Loading "/usr/lib64/qt5/plugins/kmymoney_plugins/woob.so"
Python interpreter found: 3.6.15 (default, Sep 23 2021, 15:41:43) [GCC]
Python interpreter module search paths: "/usr/lib/python36.zip:/usr/lib64/python3.6:/usr/lib64/python3.6:/usr/lib64/python3.6/lib-dynload"
Saved a copy of the embedded :/plugins/woob/kmymoneywoob.py script as "/tmp/kmymoneyvPZAen.py"
Attempt to load the "kmymoneyvPZAen" Python module from "/tmp"
The dependency 'sys' Python module loaded successfully
The 'path' Python variable loaded successfully
"kmymoneyvPZAen" Python module failed to load
Traceback (most recent call last):
  File "/tmp/kmymoneyvPZAen.py", line 13, in <module>
    from woob.core import Woob
ModuleNotFoundError: No module named 'woob'
Plugins: woob loaded
:
:

This does not appear if the KMyMoney version is compiled w/o woob support. Even though it failed loading, the plugin is visible in the plugin configuration (for me, who has compiled support for it). You may try an AppImage version (see https://kmymoney.org/appimage.html) which seems to have Woob support built in.

Unfortunately, the Appimage won't work for him on Windows.  However,  
this version  
https://binary-factory.kde.org/job/KMyMoney_Release_win64/1874/  
definitely includes woob support (according to the build logs)  I have  
not yet checked if the released Windows version includes woob.

Unfortunately, it appears the 5.1.3 released version for Windows does not include woob support.  I don't know if that is a consequence of it having  been built with mingw or if that option was just not set by whoever did the build.  That means either you need to download the daily build as linked in Comment 9, or use the Web Connect approach in Comment 7.  (While I see the woob plugin in the daily build, I cannot actually test it, as I do not have woob installed.)

Thanks for the comments so far.

Interesting "project" kmymoney is - from "lets try to use the online banking" 20h later down to "how to compile sources, or identify whats in the build".

I downloaded a nightly build yesterday. 2.1GB in size, but failed to start.

Once again - far away from the original problem of accessing the bank data .... a never ending game it seems.
Is there somewhere a description (one that can be understood by normal transaction users) for installation, determination of which modules, etc?

Revisiting this, you should start by determining which methods your bank supports (or perhaps which methods are known to work with your bank.)  Unfortunately, there may not be a single method to use with all your banks.  In this case, perhaps just choose one bank, and find what download options it supports.  Then we can work on specific documentation. 
I am working on a complete revision of the handbook, but it will be for the eventual 5.2, which may or may not be close enough to use for a 5.1 version, depending on the import method.  There are also limits on what I can do documenting methods I do not use.  Also, while it's not ready for prime time, I might find a way to share specific sections, if it would be likely to help.