Troubles configuring remote git URL

[Luc MAIGNAN]

- I've set a public key for my user USER

_ I have a self-hosted bitbucket server

- I try to configure the remote git URL as : ssh://USER@mybitbucket:port/repo

It doesn't work :-(

Two questions in fact :

- is it the good scheme for URL ?

- how specify which private key to use ? (I think it might be the problem)

Thanks for any help