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Please note that you cannot purchase/register a domain from/to Azure.
You can only delegate a domain.
This is because, Azure DNS isn't a domain registrar.
This means, the domain will always be registered to the Third party from where you purchased the domain and Name server configuration will be available only from the Third party.
Refer this link:
similar question: https://learn.microsoft.com/en-us/answers/questions/1619102/how-do-i-transfer-a-domain-over-to-azure
If you have any further queries, do let us know.
Thanks,
Rohith
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