The project contains a start point for building your own AppImage in OBS. For more information please see https://github.com/probonopd/AppImageKit/wiki/Using-Open-Build-Service

The template here is using openSUSE:Leap:15.2 as a base. So you may want to add further 15.2 based repository pathes
to the "openSUSE_Leap_15.2" repositories to get access further packages.