SSH keys require a password
How to fix
To secure them:
- Open Terminal app and type
ssh-keygen -p -f ~/.ssh/id_rsa
- Replace id_rsa with the name of the key that was reported
- Press enter, you will be prompted to enter the password
- Re-run checks, you will need to repeat steps for every key that is found
If you want to create new SSH key, the GitHub docs, provide a great starting point.