If you have made it to this page, you are looking to set up Facial ID Recognition on your ParkMobile app for your iPhone device. Here are some steps to have it work for your app:
1) Make sure your Face ID is enabled in your iPhone Settings.
2) You will need to log out of your account in your app if you are currently logged in.
3) Then navigate to the "Settings" tab and there will be an option to sign in with Face ID after you enter your email.
These instructions will allow you to login with this function of your device.