Unable to add dns record value must be a valid fqdn

I am trying to add and Verify mail250 CNAME records into the shopify DNS configuration but I am getting the below message from Shopify:

unable to add DNS record value must be a valid FQDN

Please require your support.

Thanks

I am trying to add and Verify mail250 CNAME records into the shopify DNS configuration but I am getting the below message from Shopify:

unable to add DNS record value must be a valid FQDN

Please require your support.

Thanks