Authorization with oAuth2 and Postman didn't work

Your software
My Mautic version is: v2.16.2
My PHP version is: PHP 7.3

Your problem
My problem is: I’m using Postman to test some API endpoints and I’m able to connect with Basic Authentication, but I’d like to improve security with oAuth2 authorization.
Attached you’ll find my both configurations mautic one and postman one.
I’m not able to find problem.

2022 update: with https://oauth.pstmn.io/v1/browser-callback as the Callback URL it works for me.

If you want to automate the oAuth2 process in Postman for every request, see my post: Postman automated oAuth2 Client Credentials via Pre-request Script