Please check the following：
If you set up mail forwarding, check the destination mailbox and the forwarding settings are correct.
Check your spam folder.
If you are using Outlook, check the "Other" tab next to the "Focused" tab.
If you do not receive the code after checking these factors, there may have been a problem in Microsoft system when you signed up. Please sign up again the next day.
Please note that if you repeatedly click the resend confirmation code button, the system may lock for 24 hours. If so, please leave it for more than a day and try to sign up again.