403 on DFO API with valid client_credentials token

Getting a 403 Forbidden when hitting the DFO endpoint with a token from /api/v2/oauth/token using client_credentials. The token decodes fine and has the right scope, but the API rejects it. Here’s the request:

POST https://api.niceincontact.com/api/v2/digital/omnichannel/channels
Authorization: Bearer eyJhbGciOiJSUzI1NiIs…

Any idea why the DFO API isn’t accepting this grant type?