Customize email confirmation for web admin

Hi,

I have customized the register page of our site and added First and Last name using the following instructions: https://docs.thememylogin.com/article/53-legacy-adding-extra-registration-fields

Question: How do I add the First and Last Name in the email template where the admin will see the First Name and Last name of the users who registered to our site?

Thanks!
-michfm