I think, then, the simpler way for you would be to just replace the file with patched one:
Or:
git remote add nefelim4ag https://github.com/nefelim4ag/klipper.git
git fetch --all
git cherry-pick 30d63ea9873ec65b588f74e377431286c0bf76f0
Or possibly Testing Klipper Pull Requests (It should work, but I never try that).
git fetch origin pull/6856/head
git cherry-pick 30d63ea9873ec65b588f74e377431286c0bf76f0