Yes not too complicated.

My biggest problem was that I didn’t know the difference between the public key in npub and hex Format.

At first I was wondering why the nos2x Browser Plugin didn’t accept my npub Key.

But I found an explanation from @dergigi and the solution here:

https://gist.github.com/dergigi/1ee8dc7e3da4b6572ed785ab24bc9907

“Keys exist in two formats, hex and the above mentioned npub/nsec. You can use this online tool to convert between the two formats: https://damus.io/key/ “

The rest was easy 😜