Hi @sakshi
Welcome to the Auth0 Community.
I understand you’re finding that on your Sign Up flow the Post Registration Action is not being triggered. Please note that the Post Registration Action is only triggered for users within a database or passwordless connection as per our documentation here https://auth0.com/docs/customize/actions/flows-and-triggers/post-user-registration-flow so for example, a social connection will not trigger it.
Are you using either a database or passwordless connection?
Warm regards.