https://askubuntu.com/questions/457617/are-there-any-gui-apps-that-can-create-desktop-files

When xyz.desktop file is made, move it to sudo nano /usr/share/applications/

Arronax is also a good utility for creating desktop entries.

For use specific application

https://www.cyberciti.biz/howto/how-to-install-and-edit-desktop-files-on-linux-desktop-entries/

If needed, use absolute path of application and icon.