I already bought full kontakt but I got that message ?

@Ehab Aziz If you were using Kontakt Player, the free version prior getting the full version, you need to go in Native Access and reinstall Kontakt, it should then switch to the full version.

Make sure to give full disk access to Kontakt and Ableton: How to Enable Full Disk Access on macOS

Then open Kontakt in standalone, are you able to load these instruments?

Then back in Ableton can you open the desired instruments?