Check connectivity first?

This setting controls the checks Virtualmin performs before asking the ACME provider to issue a certificate. Preflight checks can detect configuration or connectivity problems before a certificate request is made.

Test connectivity uses Virtualmin's external connectivity service to check that the domain can be reached, and also runs the domain validation checks described below.
Validate domain checks the local website and DNS configuration without running the external connectivity test.
Skip tests makes the certificate request without either Virtualmin preflight check.

Skipping these tests does not bypass validation by the ACME provider. The separate Identifier verification setting also continues to control which names and IP addresses are included in the request.