Missed the part where Azure DNS does not register domains:) So need to register and migrate stuff over to Azure DNS.
"What is Azure DNS?
Azure DNS allows you to host and manage your domains by using a globally distributed name server infrastructure. It allows you to manage all of your domains by using your existing Azure credentials.
Azure DNS acts as the SOA for the domain.
You can't use Azure DNS to register a domain name. You use a third-party domain registrar to register your domain
After you create a DNS zone for the domain, you need to get the name server details from the name servers (NS) record. You use these details to update your domain registrar's information, and point to the Azure DNS zone.
"
Hopefully this works with a non-standard top-level domain.