Typically you do process one draft at a time.
Multiple Drafts is a step more complex.
I would suggest you start with one draft.
You would have to get the credentials to access Github. This needs a personal access token from github. You have to generate one in your account under the developer settings.
A nearly matching action by Greg Pierce the Drafts developer:
Another script - it is developed by a user and I did not check all its doing, so be careful with it. It might work:
You may do it a different way via an Git App (I use Working Copy)
What do you think?