Error confirming enrollment otp authenticator

https://auth0.com/docs/secure/multi-factor-authentication/authenticate-using-ropg-flow-with-mfa/enroll-and-challenge-otp-authenticators#confirm-otp-enrollment

When trying to confirm an otp with mfa token I get the below error

{“error”:“invalid_grant”,“error_description”:“Malformed mfa_token”}

This is the grant_types used as per doc http://auth0.com/oauth/grant-type/mfa-otp. This is the same token used for enrollment and listing authenticators.