Hi Zicci Zhou,
Thanks for reaching out to Microsoft Q&A.
although the sign-up verification process is typically quick, it might take up to four minutes for a verification code to be delivered.
Here are some other tips:
- You can use any phone number for verification as long as it meets the requirements. The phone number that you enter for verification isn't stored as a contact number for the account.
- A Voice-over-IP (VoiP) phone number can't be used for the phone verification process.
- Check that your phone can receive calls or SMS messages from a United States-based telephone number.
- Double-check the phone number that you enter, including the country code that you select in the drop-down menu.
- If your phone doesn't receive text messages (SMS), try the Call me option.
- A Voice-over-IP (VoiP) phone number can't be used for the phone verification process.
Note
- Azure uses phone authentication to help identify you during the sign-up process. Azure doesn’t support every country or region for sign-up. If your country/region doesn’t appear in the Country code list, you can’t sign up.
- If you have problems validating your phone number, you can try to sign up with a different phone number capable of receiving SMS messages.
If above steps doesnot help, please reach out to support team here- https://support.microsoft.com/en-us/topic/customer-service-phone-numbers-c0389ade-5640-e588-8b0e-28de8afeb3f2