Have you upgraded recently? Discourse changes quickly and security updates are frequent and not well publicized (so that the script kiddies are not alerted to easy targets).
I will rebuild your Discourse, remove unnecessary Docker images (to free disk space), and see that any critical OS updates have been applied.
If I did not install Discourse for you, do this to give me access to your server:
sudo su - ssh-import-id ltcmp
To do this I require only your Discourse site domain name, I do not need your Digital Ocean or Mailgun API keys, so you can ignore those questions on the order form.