Unity Cloud Build can connect to Git and Mercurial repositories hosted on Bitbucket (bitbucket.org).
Unity Cloud Build can automatically connect to public repositories on Bitbucket. Copy and paste in the repository’s URL when you set up a project in Cloud Build.
If your Bitbucket repository is private, find the SSH key provided by Unity during the project’s setup for Cloud Build, and follow the instructions below to add it to your Bitbucket account.
Log in to your Bitbucket account on bitbucket.org
Open the user menu and click Manage Account
Choose SSH Keys from the left column menu
Click Add Key, and give it a label (such as “Unity Cloud Build”)
Paste the Unity Cloud Build SSH key into the Bitbucket Key field
Click Add Key
See documentation on Using Mercurial with Unity Cloud Build for details.