in terminal:
xed admin:///usr/share/applications/xampp-control-panel.desktop
then add:
#!/usr/bin/env xdg-open
[Desktop Entry]
Comment=Start or Stop XAMPP
Name=XAMPP Control Panel
Exec=sh -c "pkexec env DISPLAY=$DISPLAY XAUTHORITY=$XAUTHORITY sudo /opt/lampp/manager-linux-x64.run"
Encoding=UTF-8
Terminal=false
Name[en_US]=XAMPP Control Panel
Comment[en_US]=Start or Stop XAMPP GUI
Type=Application
Icon=xampp
save.
Thanks man! c: It works for me on linux mint 20.03