Hi Md. Azizul Kader,
Welcome to the Microsoft Q&A forum.
I understand how urgent this is, especially since the account contains important materials. Based on your description, this is a Microsoft account lock, and Microsoft Teams Free access depends on whether that Microsoft account can sign in successfully.
Please try these supported options in this order:
1, Use the Microsoft account unlock flow first
When an account shows as locked, the correct action is to complete the account unlock process by verifying your identity and resetting the password. You can start here: Microsoft account has been locked - Microsoft Support
This is the primary method for accounts locked due to unusual activity and should be attempted before any other option.
2, If you are directed to submit an “Account Reinstatement” request, use the official reinstatement form
If Microsoft’s sign-in flow indicates the account is disabled and needs review (for example, due to suspicious activity or Services Agreement enforcement), submit the request here: https://www.microsoft.com/digitalsafety/account-reinstatement
3, If verification codes are not arriving, use the official code-troubleshooting guidance
This article covers common reasons codes do not arrive and notes you may need to try another method or wait until you can access the listed phone/email. It also confirms support agents cannot send verification codes or change account details. https://support.microsoft.com/en-us/account-billing/troubleshoot-microsoft-verification-code-issues-409090c4-92b5-42b9-8ae6-bcc97e62fc48
4, Use the account recovery form only if you cannot complete the verification/unlock paths
If you cannot access any verification method, the account recovery form is the supported fallback to attempt to prove ownership: Help with the Microsoft account recovery form - Microsoft Support
Please note that this is a public user-to-user forum, so contributors cannot access Microsoft account systems or perform account-level actions directly.
I hope this helps clarify the correct recovery path and next steps.