What is Domain Control Validation (DCV)?
Domain Control Validation (DCV) is one of the checks performed prior to the issuance of an SSL certificate. This is done to verify the person requesting the certificate is authorized to use the domain associated with the order.
AutoSSL supports both DNS and HTTP DCV checks. The DNS check is performed by creating and utilizing a CNAME record while the HTTP check involves the uploading of a text file which can be validated over port 80.
More information and options for configuring AutoSSL can be found via our documentation for WHM's "Manage AutoSSL" module linked below: