Once you've got the Bitbucket integration set up and your user account connected to Bitbucket you can update issues from your commit messages. The commit message will be automatically added as a comment if you mention an issue number:
This is a comment. #1
You can also update the status of an issue by using any of the following commands followed by an issue number to update an issue. For example:
Detectable ticket update keywords:
Note: Any form of "fix" resolves an issue, not closes it.