I purchased Ultimate 15 but I can't see the tools in logic. Someone out there can be so kind and enlighten me? :-)
Do Logic and Kontakt 8 both have full disk access? How to Enable Full Disk Access on macOS
Have you tried to open Kontakt 8 in standalone? Do the tools show there? Check in default view. Once you open a library you should be able to see them here:
If they're missing try resetting K8's database: