Trying to update the app on my LG V20 - getting an error - authentication is required. You need to sign into your google Account. What account?
Keeping your phone up-to-date is essential. Do not worry, we'd be glad to help. The LG V20 is a Google phone, and should have a Gmail address set up on as it's the backbone of the phone.
Do you ever download apps out of the Play Store? What happens when you click on the Gmail app?