[ssh] Solve "Agent admitted failure to sign using the key"

ssh -T git@github.com (Tutor : Generating SSH Keys - must add ssh key to github)

Agent admitted failure to sign using the key.

Permission denied (publickey).

ssh-add

Identity added: /home/ABC123/.ssh/id_rsa (/home/ABC123/.ssh/id_rsa)

ssh -T git@github.com

Hi ABC123! You've successfully authenticated, but GitHub does not provide shell access.

Reference :

• SSH 連線出現 Agent admitted failure to sign using the key 解法