How to do further work on github PR before merge?

Say someone submits a PR from a forked repository to my repo on Github. It's 99% OK but for the remaining 1%, I don't want to go back and forth with the PR-review and he-fix and I-review-again cycles, and want to go straightforward and fix them myself.

Is there a way to do further work on github PR myself, i.e., my changes show up in his PR before merging it?

• The merge that PR into a new dev branch seems not to be an option, and
• The Checking out / Modifying pull requests locally doc doesn't work for me:

$ git fetch origin pull/11
fatal: couldn't find remote ref pull/11

And the normal git pull command to manually pull the changes of the PR into my local repo doesn't work for me either:

$ git pull
Current branch master is up to date.

$ git branch -a
* master
  remotes/origin/HEAD -> origin/master
  remotes/origin/master

As when I check the branches in github, there is no branch for that PR:

You can do a git pull command to manually pull the changes contributed in the PR into your current branch, whether it is the main branch or a development branch. Just look below the pull request on GitHub and click the little link that says "command line instructions". You can ignore most of the instructions and just look for the one line that starts with git pull.

Then make whatever commits you want to (on top of the pull request, without squashing or amending the commits) and push your changes to wherever is appropriate (e.g. the master branch of your repository on GitHub).

You can simply add more commits to the same branch and push them. GitHub Pull Request will be automatically updated with those changes.

Pull Request is a GitHub-only concept. If you're using git, you should checkout the corresponding branch. If you want to checkout a pull request, you should use GitHub CLI instead of git directly (in the documentation linked in your question, notice that command is gh, not git).

If you don't see any other branches in your repository (as per screenshot in the updated question), it's possible that PR was opened from a forked repository by someone else. In that case you can't edit code to be merged directly. Your options:

• Ask the PR owner to edit the code as you'd like.

• Merge the PR and edit the code as you wish afterwards.

• Close the PR and manually merge the code you want. Wouldn't recommend this, since it may be considered rude to the PR owner, taking credit for their work. But if you still want to do it, clone their repository to your computer, checkout the correct branch, merge it into your repository, and push code. See this answer on how to merge code between different repositories.

Install gh by saying brew install gh. Then say

gh pr checkout 11

(assuming that that is the correct number of the PR). You can now edit, add, commit, and push. Your commit(s) will be appended to the PR at GitHub.