Prepare G-Mail account for Outlook | Setting up Gmail account in Outlook

You now have to enable two step authentication and create an APP Password to be able to use your G-Mail account in Outlook.

https://support.office.com/en-gb/article/Prepare-your-Gmail-or-Google-Apps-account-for-connecting-to-Outlook-and-Office-365-b650957d-4446-425a-ab78-01b89cbead93

My opinion,

Complete ball ache!