Hi @BrendonKoz ,
We have a similar issue on another template image. Can you open /etc/nginx/sites-enabled/nginx-passbolt.conf, you should see this line:
server_name _;
Can you replace the underscore with your passbolt domain name:
server_name passbolt.example.com
Then reload nginx:
sudo systemctl reload nginx.service
Once done, certbot should be able to edit your nginx configuration file, you can restart the sudo dpkg-reconfigure passbolt-ce-server.
Let me know if it fixes your issue.
Best,