I can't change my country/region when I sign up Azure, it was grey and I can't click it. What should I do?

I can't change my country/region when I sign up Azure, it was grey and I can't click it. What should I do?

You can follow along here.
https://docs.microsoft.com/en-us/azure/cost-management-billing/manage/change-azure-account-profile#update-your-country-or-region
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