Passwordless server to server (golang)

I tried to implement passwordless authenticaiton on server to server app. I succeded using twilio and sent an sms to a phone number.
I would like to verify the code but It seems like it is not clear how to handle it.
On this page : Authentication API Explorer
it is written that /auth/ro is disabled and we need to activate this API. it also suggests to look on the grant_types documentation at : https://auth0.com/docs/applications/application-grant-types
but on this page they write that : “Those implementing Passwordless Authentication should use universal login instead of the oauth/ro endpoint.”

The problem is that I cannot use universal login since it server to server authentication.

How should I implement that?
I cannot use : Lock or Auth0.js

Hi @davidh,

I apologize for the delayed response on this question. I would like to reopen the topic for discussion and provide some assistance if possible.

Typically you would want to implement a client credentials grant for a M2M connection like this. If there is no user in the transaction it is going to require this type of flow.

Thanks,
Dan