If you go to the logout screen e.g. by Ctrl+Alt+Del, where you can choose between standby, hibernation, reboot, shutdown and logout, you can tab between controls. Once "logout" is focused, the next hop will lead you to the "okay" button and then to the "cancel" button. Issue: Both the "okay" button and "cancel" button do not work if you press the enter key now.
You use the spacebar, not the return key. That's the general way to simulate a click on the focus item.
(In reply to Nate Graham from comment #1) > You use the spacebar, not the return key. That's the general way to simulate > a click on the focus item. Is it? If I have a Plasma context menu open I can simulate a click by pressing the "return" key and not "space". If I have kicker open, I can open an application by hitting "return". If I have KeePassXC open, entered my password, I log in by hitting "return". Not sure where using the spacebar is actually the "general" way. :)
It's the general way to virtually click on a UI element that you have focused with the keyboard. Not working in menus is a bug, darn. In Kicker, it doesn't work because the spacebar is consumed by the search field. Keepasscx isn't applicable; if you actually tabbed over to the "ok" or "login" button and hit the spacebar, I'm reasonably confident that it would in fact work.
(In reply to Nate Graham from comment #3) > Keepasscx isn't applicable; if you actually tabbed over to the "ok" or "login" button and hit the spacebar, I'm reasonably confident that it would in fact work. Indeed, in this case both "return" and "space" work.