Programming Phoenix LiveView: B03 (page 56-57) auth exercise

Dear Sophie.
I tried to do the “Authorization” exercise and have two questions:

1. When trying to plug in an email-service, I found the function “&Routes.user_confirmation_url(conn, :confirm, &1)” in “user_confirmation_controller.ex”.
   I wasn’t able to find this function.
   Where is it located or how is it created dynamically?

2. I added the “username” field without problem, but when I set it to unique and made it safe with “unsafe_validate_unique(:username, Pento.Repo)” some tests failed. I tried to fix them via modifying the fixture()-Function, but still two test concerning the uniqueness of the “email” failed.
   Is there an easy way to get the generated tests running, when adding a second unique field?

Thanks for your superb book.
I learned a lot from this exercise, especially the sending of the confirmation-email via Bamboo and Sendgrid.

Best wishes from Heiko