Passwordless Connection for AWS SNS using custom the SMS Gateway docs

Hello, I’m trying to get a better understanding of implementing a custom SMS gateway using docs at the following link: Set Up Custom SMS Gateway for Passwordless Connections

Can someone answer my two questions below?

  1. Where do I use the code shown in the link within my auth0 dashboard?
  2. How do I access my bearer token if this process precedes authentication?

For better context, I am working on integrating amazon SNS for passwordless login.

Thanks so much.