Hi @joheben! I moved this post to a new topic so it doesn’t get mixed up with the previous one.
@rg305 is right, you can list your certificates that way, but I’m afraid it doesn’t list the validation methods used.
Have you read How to stop using TLS-SNI-01 with Certbot yet? The main thing you need to do is check that your Certbot is up-to-date (at least 0.28.0). If it is, there’s a 99% chance you’re fine. The only way you might not be fine is if you passed a special flag to choose TLS-SNI, or if you have an unusual firewall config.
Out of curiosity, how did you issue certificates on your failover server previously?