How to merge master branch into main branch in GitHub

I am trying to merge two branches in GitHub, but I am not sure how to do so – I have tried various ways to no avail.

I have two branches in GitHub, one is just the “main” branch that was created when I created the repository in GitHub – it only contains a blank README file, the other branch is my “master” branch and that is where all my project files exist.

I have already pushed my master branch into GitHub, so I have two branches, my “main” branch and my “master” branch in GitHub, but now I am stuck.

What I want to do is merge my master branch into my main branch.

How can I do this?

If there’s a way to do it both in Git and GitHub I would appreciate if you could show me both ways.

Thank you in advance!

Did you check the documentation?

Are you using GitHub Desktop or using the command line?

Or, maybe this would help?
https://www.togaware.com/linux/survivor/Git_Merge_Master_into.html