There ist no geolocation functionality anymore. It worked in older versions but now it is missing! No tab, no editor etc. This is a very important feature.
It's a packaging problem. digiKam was probably compiled with Marble support. Report this problem to packager. Note : you can use AppImage bundle for linux that we provide. Look in digiKam download page. This one has Geo-location feature of course. Gilles Caulier