This line works on kubuntu and neon, but not Enveavouros KDE:
pkexec env DISPLAY=$DISPLAY XAUTHORITY=$XAUTHORITY KDE_SESSION_VERSION=5 KDE_FULL_SESSION=true dolphin
Here is the output from the above message:
“Session bus not found\nTo circumvent this problem try the following command (with Linux and bash)\nexport $(dbus-launch)”
I tried the export. Made no difference.