- OAuth 2.0 - Error - 311 - ERR_UNSAFE_REDIRECT


I am using the postman application, not the addon.
I tried to access the Adobe User Management API through postman with OAuth 2.0. When I try to request the access token with the following settings (changed them 1000 times by now):
Callback URL (currently): tried postman callback url, local callback url and many others.
Auth URL: (tried with v1, without v1, with http, without any others)
Token URL: (same here)
Client Auth: Send client credentials in body

When the login prompt should show up I see a blank page instead and the logs show:

[17736][1580799848967][main][info][“OAuth2WindowManager~startLoginWith - Received redirect on auth login window”]
[17736][1580799848968][main][info][“OAuth2WindowManager~startLoginWith - URL did not match the registered callbackURL, so skipping”]
[17736][1580799848973][main][info]["OAuth2WindowManager~did-fail-load: Error with code ",-311,“ERR_UNSAFE_REDIRECT”,“”]
[17736][1580799848973][main][warn][“OAuth2WindowManager~did-fail-load: No history URL matched with the callback URL”]

That’s a chromium error which says the redirect is not allowed if I’m correct.
Does anybody has an idea on how to fix this?

Thanks and Greetings