This article is for the error:
It seems you tried to log in with a user that does not have Google Display & Video 360 (Campaign Manager) enabled. Please try again with another user account.
This means that your Google account has not been properly set up to access Campaign Manager. Please check with your DV360 System Administrator to make sure the account you are using has the correct permissions to access this. See also General Data Source Access Requirements for more information on what is required for your account.
Note: Campaign Manager and Bid Manager are still separate APIs and may require different permissions to access. Make sure you are using the correct connector and have permissions to that specific part of DV360 for your account.