You can just use the
git flow feature publish <name>this will publish your feature branch to your origin (like Bitbucket). Then you can create the pull request there and merge it into develop. After that is done, you need to manually delete the local feature branch.
The only command you can not use is
git flow feature finish <name>. This works fairly well and you can still use most of the git flow helpers.
The same goes for releases. I found this article helpfull: https://blog.axosoft.com/pull-requests-gitflow/
As well as https://community.atlassian.com/t5/Bitbucket-questions/git-flow-feature-finish-and-pull-request/qaq-p/347877
Hope this helps a little. There is just not the one perfect solution to this problem.