Hi @rajivk,
Thanks for reaching out to the Auth0 Community!
I understand that you would like to enforce MFA for a single user.
In this situation, I recommend using an Auth0 Post-Login Action to selectively enforce MFA for the user.
Please review our How To Enable MFA For A Subset of Users FAQ which goes into further detail on how to accomplish this.
If you have any additional questions or need help with implementation, please feel free to reach out.
Thank you.