Note: only do this on a feature branch if you are the only developer working on the feature branch, otherwise you will break the history for all other developers working on that branch.
This is safe to do on develop and master in your fork, because you will never be working on that and will always want the latest updates to those branches,
This will bring in all the latest changes from the main develop branch into your develop branch and then replay all your changes on top of that,
$ git checkout develop
$ git fetch upstream develop
$ git rebase upstream/develop
$ git push origin develop
This is useful to do before creating a merge request, because it will resolve any conflicts that you may have with the merge request. Rebase will ensure that git replays all of your commits on top of the latest code in develop:
Fetch and rebase your develop branch as above, then:
$ git checkout feature/my-branch
$ git fetch upstream develop
$ git rebase upstream/develop
$ git push origin feature/my-branch