api – Google OAuth2 -> redirect to the login page

I will try to connect to the content API to buy through the API.
I have tried some different forms of OAuth (for example, "three-step method" with passcode and baerer-token) but for a specific integration I need the "credentials-oAuth".

Currently I have tried the following:

https://accounts.google.com/o/oauth2/v2/auth?
client_id =[my client id]Y
scope = https: //www.googleapis.com/auth/content&
redirect_uri =[some random request bin -> added in Authorised redirect URIs ]Y
response_type = code

If I call this through Postman, I will be redirected to the Google sign-in page. But why?

How can i solve this problem?

BG
David