MFA with Ruby o Rails

Hi people,

I am trying to connect our service with Auth0. Currently we are using “devise” to handle our authentication process. I was able to connect with Auth0 Universal logic so we can have devise and auth0 logic working together using the API (for creating user or importing users in Auth0 and so on). But, there is a requirement to implement and manage MFA, I have the problem that the Universal logic is not returning (sending to callback method in our system) the Access Token correctly or mfa token to handle MFA Management (add, list or remove MFA devices).
Any idea of what I am doing wrong? My idea is to get the mfa token right after logic so I can construct the GUI for MFA Management.

It seems to be hybrid implementation between Authorization Flow and SPA Flow