How to access a git repository using SSH?

1. install git and xclip

sudo apt-get update
sudo apt-get install git
sudo apt-get install xclip

2. Generating a new SSH key and adding it to the ssh-agent

ssh-keygen -t ed25519 -C "your_email@example.com"

3. Copy the SSH key to your clipboard

xclip -selection clipboard < ~/.ssh/id_ed25519.pub

4. Adding a new SSH key to your GitHub account

login your GitHub >> your profile >> Settings >>
SSH and GPG keys >> New SSH key >> add a descriptive label for the new key >>
Paste your key into the "Key" field(Ctrl+C) >> Add SSH key

references

https://askubuntu.com/questions/527551/how-to-access-a-git-repository-using-ssh
https://docs.github.com/en/free-pro-team@latest/github/authenticating-to-github/connecting-to-github-with-ssh