To create a pull request in Bitbucket, you first need to update your branch with new code that you want to be reviewed, then open the Bitbucket website and navigate to the repository's Pull Requests page. From there, click Create pull request, selecting the sub-branch you want to merge into the master branch, and specifying reviewers who will review your code. Once submitted, the reviewers can view your branch, compare it with the master branch, leave comments, and eventually merge your branch's code if they're satisfied with your work.