Update the name server records at the domain registrar to point to the Azure DNS name servers is correct.

When you create a public DNS zone in Azure you are given a set of Azure DNS name servers that must be registered at the domain registrar so that the parent zone delegates the domain to Azure. Updating the registrar name server records delegates the domain to Azure and makes the records you add in the Azure zone reachable from the public internet.

Create the SOA record inside the example.com Azure DNS zone is incorrect. The SOA record is part of the zone data and Azure creates a valid SOA for the hosted zone, but adding or editing an SOA inside the hosted zone does not cause the parent zone to delegate the domain to Azure.

Add NS records to the example.com zone within Azure DNS is incorrect. NS records inside the hosted zone describe the authoritative servers but they do not perform the delegation at the parent registrar. The registrar must be updated so that the parent zone points to the Azure name servers.

Edit the SOA record at the domain registrar to reference Azure is incorrect. Delegation is performed by updating name server records at the registrar and not by changing an SOA at the registrar, and registrars generally publish NS records rather than using an SOA for delegation.

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