source:
https://docs.github.com/en/authentication/connecting-to-github-with-ssh/generating-a-new-ssh-key-and-adding-it-to-the-ssh-agent



# Generating a new SSH key
ssh-keygen -t ed25519 -C "your_email@example.com"



# Adding your SSH key to the ssh-agent
eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_ed25519





# Adding a new SSH key to your GitHub account
https://github.com



 
# Testing your SSH connection
ssh -T git@github.com














# clone your github repository by ssh's link
git clone git@github.com:xxx/xxx.git
# View the existing remotes
git remote -v







# set a remote SSH URL in git
git remote set-url origin git@github.com:xxxx/xxxx.git
git remote -v






# done
git init
git add .
git commit "update"
git push