I don’t believe there is a configuration to allow you to add fields to the autogenerated live views for registration. The reason for this is that, if you want to build a custom registration experience you should make a custom liveview. Some notes on that here: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwis3_GV54KEAxUOMlkFHTH6Av0QFnoECA4QAQ&url=https%3A%2F%2Falembic.com.au%2Fblog%2Fcustomising-ash-authentication-with-phoenix-liveview&usg=AOvVaw3NEsQEl07LtoB5fT-FU3eS&opi=89978449

My suggestion, however, would be to allow users to add those fields after registration in a custom settings page of your own design. You can forward users there after registration as well, using a plug in your router that checks if the current user has a first name and last name. If they don’t, you can redirect them to the settings page with a flash message asking them to fill in their first and last name (or something along those lines).

Thanks for your reply, @zachdaniel.
I’ll implement your plug suggestion.