Ok, this is a more general question. Maybe this belongs in another Topic, but i can explain it anyway (also for @Virtualchronos)
I made a pull request (PR). This means, that I cloned the original repository and did my changes in a so-called feature branch (pwm_sync_channel in this case) in my “own” repo.
Then I requested on the original repository’s page, that my feature branch shall be merged with the master branch on Kevins original repo.
This request is https://github.com/Klipper3d/klipper/pull/4128. From there, you see the “Cirromulus wants to merge 4 commits into Klipper3d:master from Cirromulus:pwm_sync_channel” right on top. There you find 1. my repo’s link, and 2. the name of the feature branch.
So, to check this out, you go into your local klipper folder and add another remote (read: repository).
Your original (kevins) repository will be called origin.
To check out my feature branch, you type git remote add cirromulus https://github.com/Cirromulus/klipper.
With this, you have “access” to the original repo and to mine.
Then, to get the newest stuff, type git pull --all. This will get the newest versions of all branches (including the one you are currently on, probably master).
Then, you can check out my branch (git checkout cirromulus pwm_sync_channel).
Restart klipper for it to have have effects. If something breaks, you can always git checkout master for the original, newest branch.