Create workflow with manual trigger in a branch

I have a git repo with a feature branch. I need to add a GH workflow with manual trigger (workflow_dispatch). Since I am testing out a few things, I don’t want to add the workflow directly to the main branch, but on a feature branch. But when I try to add a new Action, it by default adds it to main branch, instead of feature branch. Also, when I try to trigger the workflow from my feature branch, it doesn’t list my branch in the dropdown. Is it possible to create a workflow (to be triggered manually) in a specific branch? If yes, how?

It’s not possible yet, from what I know.