HOW TO SET UP "TIME MACHINE" IN NEW 2021 MAC WHEN NOT INSTALLING AN EXTERNAL DEVICE?
WHEN I CLICK ON "SYSTEMS SETTINGS" THEN "GENERAL" AND "TIME MACHINE, I GET ONLY A WINDOW ASKING "ADD BACKUP DISK" (WHICH I'M NOT INSTALLING). CLICKING ON 'ADD BACKUP DISK" OPENS ANOTHER WINDOW, "NO AVAILABLE TIME MACHINE DESTINATIONS"
iMac 21.5″, macOS 10.15