Noopl uses Sign in with Apple when setting up and registering your Noopl device. This enables you to use your existing Apple ID and not have to create a new account (or password) just for Noopl. It also allows you to be in control of your personal information.
In order to use Sign in with Apple, your device must have two-factor authentication enabled. Two-factor authentication is an extra layer of security for your Apple ID designed to ensure that you're the only person who can access your account, even if someone knows your password.
Follow these instructions to set up two-factor authentication on your iPhone.