Hello, thank you for reaching out to Microsoft Q&A.
If you tried to sign in and received a message that you're account is blocked, it means that your account's recent activity might have violated Microsoft's terms of use.
You can first try the Outlook sign-in helper tool below to unblock your account.
If you're still having issues, you will have to use the account recovery form.
Detailed steps on how to use the Account Recovery Form can be found here: https://support.microsoft.com/help/b19c02d1-a782-dee6-93c3-dc8113b20c42
Remember to use a familiar device from which you've frequently accessed your Microsoft account, as well as a familiar location. Microsoft will review your responses and respond within 24 hours. If you are verified, instructions on how to log back into your account will be sent to you, and if you are not verified, you will need to submit the Account Recovery form again. You can do this up to 2 times every 24 hours.
Alternatively, you can try the account reinstatement form here for Microsoft to review the reasons why your account was disabled.
https://www.microsoft.com/ko-kr/concern/AccountReinstatement
Let me know if you still need more help.