Authorize bash to access GitHub protected branch - bash

Question

This might be a silly question, but here I am after two days of head banging 😔
I'm currently working on a GitHub Actions job, that would at some point git push to a protected branch (master, actually). However, once it gets to this step, the job fails with a "You're not authorized to push" error message:
error code GH006
In my situation, the first time it happened, it meant that the worker (CLI, bash) is not authorized at all. So I went to log it in a dedicated GitHub account, — and this is where I'm stuck for a couple of days now.
So, how do I login to GitHub account via CLI?
The things I've tried:
Pushing to master manually
This works without errors, since the authorization is OK, — but it is obviously not automated, which is what I'm after.
A couple of details:
I was using Windows 10, whereas the job is set up to run on "ubuntu-18.04";
I've removed all GitHub-related logins from Windows Credential Manager before performing git push, and set them up again via GitHub Login dialog window.
Manually pushing under unauthorized credentials fails, as expected.
git remote set-url origin "https://$username:$token#github.com/my/repo"
This didn't seem to give any effect. I've tried both setting URL of the existing remote and removing-than-adding remotes with different URLs, — both approaches seem to work (not work) the same.
None of the configurations below worked:
steps:
- run: git remote set-url origin "https://$username:$token#github.com/my/repo"
- run: git push origin master
steps:
- run: git remote remove origin
- run: git remote add origin "https://$username:$token#github.com/my/repo"
- run: git fetch origin --all # with and without this step
- run: git push origin master
curl -u "$username:$token" https://api.github.com/user
This is suggested in the docs, and it does succeed, but the login does not persist until git push — even if the pushing happens in the same step. I suspect, there might be a cookie-related solution, but I'm not sure how do they work in a non-browser environment. Also, I believe that this API is designed for different purposes.
Both of these configurations failed:
steps:
# separate processes
- run: curl -u "$username:$token" https://api.github.com/user
- run: git push origin master
steps:
# same process
- run: |
curl -u "$username:$token" https://api.github.com/user
git push origin master

Answer 1

actions/checkout#v2 will now configure and persist authentication when setting the token input. You shouldn't need to configure the origin URL manually.
- uses: actions/checkout#v2
with:
token: ${{ secrets.PAT }}
- name: Create a change
run: echo "test" > test.txt
- name: Commit change
run: |
git config --global user.name 'Your Name'
git config --global user.email 'your-username#users.noreply.github.com'
git add -A
git commit -m "Add test file"
git push
According to this comment on the GitHub forums, the PAT must be created from an admin/org owner account. A collaborator with write access is not enough to push to protected branches.