SSH Authentication still asks for OAuth

Question

I have set up a SSH protocol with a SSH Key, created by Putty. In Bitbucket, i was able to insert the OpenSSH Public Key and on my Laptop, I was able to connect to Bitbucket by the ssh-agent. Also i started Pageant and connected to Bitbucket.org using Putty.

Now i wanted to use the SSH Key in Sourcetree. There it is possible to add an Account, that uses the SSH protocol, but for credentials it still uses OAuth. (Basic selection has this bug, "unexpected character")

Is there another way to authenticate other than OAuth or Basic?

I thought, thats why one would use SSH?

Thanks for your Feedback

Lukas Angst · Answer

Found the problem. Sourcetree needed an app password. Here, it is important to just use lower case letters for the password name.