Hi @ABCTesting ,
The New Universal Login Page (login page hosted by Auth0) can be set to use: social login (like google) + passwordless but not Username-Password-Authentication + passwordless. So, unfortunately, what you are looking for is not something out-of-the-box that Auth0 provides.
This doc (the problem statement) shares steps to created a username-password account with Auth0 Actions while the user logs in via passwrodless and link them later together to have phone + email data on the user profile. This just creates a pipeline of passwordless + username-password at the login instead of setting separate connections to be chosen but may be a reference for you.
This is the management API endpoint for linking accounts.
Client side linking and server side linking.