Digital Ocean public key denied

gistfile1.txt

In DO problem with paste new key via web console, below description how to do it via terminal on mac

1. Recovery password in DO to root
2. After login to root via console, check the list of users

(for ubuntu)
# cut -d: -f1 /etc/passwd

3. Switch to another user if is created if not create new user or proceed with root
https://askubuntu.com/questions/410244/is-there-a-command-to-list-all-users-also-to-add-delete-modify-users-in-the
4. change permission to server 

# sudo nano /etc/ssh/sshd_config
PermitRootLogin prohibit-password to PermitRootLogin yes 
PasswordAuthentication no to PasswordAuthentication yes

5. If the ssh key is still conflict and you can't access via terminal remove ssh for root

# nano ~/.ssh/authorized_keys

delete full key

6. Restart ssh service

# sudo systemctl restart ssh

7. Now in terminal add your key

# ssh-add -K

8. Try to login via terminal ssh user@123.123.123.12
9. add new ssh to authorized_keys

# nano ~/.ssh/authorized_keys 

Paste new public key and save