Authentication fails for Lightroom API

Hey,

I set up an integration in my Adobe developer console and followed the OAuth 2.0 guideline for gathering an access token. The problem is that I am not able to access any of the Lightroom API services (e.g. catalog) using this token. I tested it with the following command: 

curl -H "x-api-key: [API_KEY]" -H "Authorization: Bearer [ACCESS_TOKEN]" https://lr.adobe.io/v2/catalog

The response from the Adobe server is: 

while (1) {} {
    "code": 4300,
    "description": "Access is forbidden"
}

I made the following observations that might help to find the problem:

- When I grant my integration access on the user side, it only asks for permission to log me in. According to the OAuth 2.0 guideline, it should request some more permissions. 

- When I request the access token using the authorization code, the reply only contains access_token, sub, id_token, token_type and expires_in. According to the OAuth 2.0 guideline, it should return information about the user in addition. 

Do you have any idea how to fix that problem? I am grateful for any advice. 

Thank you, 
Best, 

Sebastian