setting up mail app with gmail account

Hello, I am trying set up the apple mail app with my gmail account. I click the + to add the account. I click "google" for the account type, and I get a message saying "Google requires completing authentication in Safari". I click "open Safari". A private Browsing window appears prompting me to log into my google account. I put in user name, password and the 2 step verification code. I get a window saying MacOS wants access to your google account. I click "allow", and then back on the mail accounts screen I get Authentication Failed. I believe this is happening because it is opening up a Private Browsing window. I changed Safari's preferences to open a up a new window instead a private one, but it will still only open a private window. Can anyone explain why it is still open a private window?