Start a challenge when the user is already enrolled with at least one email magic link authenticator
Use a short-lived token obtained from the Server API's Track Action endpoint. The token is valid for 10 minutes and should be passed in the Authorization header as 'Bearer {token}'.
The ID of the email authenticator to use. Only required if the user has multiple email authenticators and you want to target a specific one.
OK
The ID of the challenge. Pass this ID back to check if the user has clicked on the magic link and finalize the challenge.