I couldn’t connect my private repository with the cPanel via SSH

I have generated public/private key, then copied it to deploy keys in the GitHub repository settings, but I got this error message:

Permission denied (publickey).

Is this because I am using shared hosting, from Godaddy although I have access to git, ssh, and terminal in the cPanel?

I want this because I want to upload using git cleverly instead of manual uploading using Filezilla..