From a similar question at https://learn.microsoft.com/en-us/answers/questions/739221/resource-cannot-be-created-because-the-subscriptio.html (answered by brtrach-MSFT)
For certain services such as Azure custom domains and SSL certificates, these products require you to have a longer payment history within Azure to prevent malicious activity.
If you need a custom domain, a work around would be to use a 3rd party domain provider, such as GoDaddy. (Azure uses WildWest Domains, which is a subsidiary of GoDaddy)
I recommend you try to reach out to Azure Billing to ask more questions at https://azure.microsoft.com/en-ca/support/create-ticket/
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