Problem with mx

In can´t delete the enter Domaim-> fhxjwiqj.epizy.com// Data-> mx.byetcluster.com in my own domain appear this message Error #459346986 Please contact supportMX Records can not be altered on subdomains.
My domain is ugtdigiteldocumentos.es
Thx

If your domain name is ugtdigiteldocumentos.es, you can configure MX records for ugtdigiteldocumentos.es. MX records in the list which are not for the domain ugtdigiteldocumentos.es, do not affect the domain ugtdigiteldocumentos.es.

The MX record for the “main domain” fhxjwiqj.epizy.com cannot be deleted, but will under no condition affect email delivery for your actual websites either.