Perhaps you have another user that can connect, but if not, you may have lost SSH access to the server.
If the server/site can stand the downtime, and you have copies of files and data, you could destroy/rebuild the server (with whatever setting you want for sshd_permit_root_login).
If the server must stay up, you can restore root access on Digital Ocean.
In the unlikely event that you have staging and production on the same server (not recommended) and have edited the admin sudoer password for staging or production, note that it’s the same admin user on a single machine, so admin should have the same sudoer password in your Trellis configs for both environments.