[Tutorial] How to resolve CardDAV account verification failed with correct password in iPhone

I am wondering why iPhone keep poping up the error message although I have key in the password correctly. Continue read for the resolution.

The answers provided helped me resolve my CardDAV verification issue. Here are the exact steps I took:

Sign in to your Google Account at: https://myaccount.google.com/
In the Sign-in & Security section select: ‘Signing in to Google’
Select ‘App Passwords’
From the dropdowns: Select the app (contacts) and the device (iphone)
Follow the instructions in the pop-up to enter the verification code as the password for your google account on your phone.