Error creating new authz :: Policy forbids issuing for name - Azure

Hi,
I’m trying to setting up SSL for my Microsoft Azure instance, but I got:

Domain “serverwifi01.cloudapp.net” registration failed { “type”: “urn:acme:error:rejectedIdentifier”, “detail”: “Error creating new authz :: Policy forbids issuing for name”, “status”: 400 }

Let's Encrypt doesn't issue for these "*.cloudapp.net" instance names. You will need to have your own domain name and point it at the Azure instance.