Software not using Dolphin open/save file picker

This seems to work for some software, but not all:

sudo vim /etc/environment

GTK_USE_PORTAL=1
GTK_DEBUG=portals
XDG_CURRENT_DESKTOP=KDE

For other software, it's necessary to install the rpm, because these don't use portals and instead directly call the desktop environment's window methods, which hasn't been included in the flatpak. This impacts libreoffice and possibly others.

For yet other programs (e.g. audacity and filezilla) they still display the gtk file dialog even when installing the rpm. Most likely these programs don't support using portals for the file picker and also don't support the desktop environment directly either. I have no solution for these yet.