How to verify your commits with GitHub using SSH

thisneedsbetterdocumentation.txt

git config --global user.email "Your Email Used On GitHub.com"
git config --global commit.gpgsign true
git config --global gpg.format ssh

If you already have a high-complexity SSH key, skip this.
  ssh-keygen -t ed25519 -C "optional comment"

cat .ssh/id_ed25519.pub 
git config --global user.signingkey /home/USER/.ssh/id_ed25519.pub 

https://github.com/settings/keys
  Copy-paste your key -- set the type to Signing key. 
  (This assumes you already have this key in the Authentication section, that you've been using it, if not add it as an auth type key too)
  
git commit -am "Now with signing key?" && git push
And open your GitHub repo and check if the badge appears. 
Disclaimer: I wrote this quickly, if I missed something, please let me know. GitHub's helpdocs have all these steps scattered all over. 
Do your part to secure software supply chains from attack.