I'd be happy to help, but you didn't actually tell me the problem^^
I don't understand where I should go exactly to activate the base, and of the places I went, none of them gave a clue, I know that to activate the base I need a key but I don't know where in what area of the map it is.
You need to find the old vampire crypt, the key is inside.It's in the east of the map, basically as far east as you can go.
ok, there I found it, it was difficult to find it because of how far away it was, thanks for the help