I don’t know the phpstorm interface for Git, but in the command line I’d do the following:
git checkout developgit pull origin develop-> this fetches the remote version of the develop branch and merges it (or rebases it, depending on your pull strategy) into/onto your local branch. This way the local and the remote versions of develop are the samegit checkout feature-brachgit rebase develop
If there are any conflicts – resolve them. After that you can create a pull request against develop.