Hi,
It's most likely your MCP account in this case, you can change your Microsoft account password by following the guide here:
Change your Microsoft account password
https://support.microsoft.com/en-us/help/4026838/microsoft-account-change-your-password
More information here:
Microsoft account security info & verification codes
https://support.microsoft.com/en-us/help/12428/microsoft-account-security-info-verification-codes
Best regards,
Leon