Open the Gotbackup installer you downloaded (a file ending in .dmg).
Drag the Gotbackup app into the Applications folder.
Grant Full Disk Access to Gotbackup then open Gotbackup from your Applications folder.
If you see a pop up like this, click open.
Sign in to your Gotbackup account.
Click Start Backing Up.
Click Close.
Finished! Gotbackup will now backup your entire computer to the cloud in the background.