Seems like that the private key you are using to access the remote repo does not match any public key in the repo.
Does your useraccount on bitbucket.org have the right key and does the account have access to the repo.
Pls. have also a look to
We’ve been building a plugin to integrate Bitbucket Server and Jenkins CI, and I’m excited to announce that our alpha is ready to download and install. It lets you seamlessly configure a Jenkins job ...
Connect with like-minded Atlassian users at free events near you!Find an event
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no Community Events near you at the moment.Host an event
You're one step closer to meeting fellow Atlassian users at your local event. Learn more about Community Events