Another way in QuickBooks Mac 2016 or 2019 is to go to QuickBooks->Preferences, click on email, and configure QuickBooks to talk to gMail. The settings will be similar to those that you have set up in Apple->System Preferences->Internet Accounts under Gmail.
You have clicked a link to a site outside of the QuickBooks or ProFile Communities. By clicking "Continue", you will leave the community and be taken to that site instead.