They can be used in any local terminal. I use Cmder.
Navigate to the plugin folder
cd wp-content/plugins/my-first-plugin
Initialize Git specifically in this folder
git init
Add all plugin files to the index
git add .
Making the first commit
git commit -m "Initial commit"
Specify the default branch as main
git branch -M main
Link a local folder to a repository created on GitHub
git remote add origin https://github.com/...
Pushing code to GitHub
git push -u origin main