OAuth authentication fails when trying to run Account Linking in Google Assistant

In order to obtain Google Account information from Google Assistant, I am trying to run Account Linking by referring to the URL below.

https://qiita.com/flatfisher/items/1f39de99728d8717c73b

Edit Actions on Google Overview

with Outh authentication ·Authorization URL
　 https://accounts.google.com/o/oauth2/v2/auth

when configured. Google accounts cannot be used as Auth endpoint urls per account linking policy
encountered an error.

If you know how to deal with it, please reply.