Certbot won't authenticate my subdomain

Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. crt.sh | example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.

My domain is: api.trendstudentstorage.com

I ran this command: sudo certbot --nginx -d api.trendstudentstorage.com --expand

It produced this output:
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Requesting a certificate for api.trendstudentstorage.com

Certbot failed to authenticate some domains (authenticator: nginx). The Certificate Authority reported these problems:
Domain: api.trendstudentstorage.com
Type: unauthorized
Detail: Invalid response from http://api.trendstudentstorage.com/.well-known/acme-challenge/ELkRRLHyFkl3hpiI1QSExF9lWJTb7nDuVQUk9l94ekE: 404

Hint: The Certificate Authority failed to verify the temporary nginx configuration changes made by Certbot. Ensure the listed domains point to this nginx server and that it is accessible from the internet.

Some challenges have failed.

My web server is (include version): Nginx

The operating system my web server runs on is (include version): Ubuntu

My hosting provider, if applicable, is: Digital Ocean

Welcome @Marois2000

It looks like you are still changing your DNS setup. You were using some sort of URL or Domain forwarding service but now don't have any A record for your IP.

Let us know when you finish your setup