Need Help with OpenEMR API: Encountering 'Invalid Client' Authentication Error

but always the same error

ChatGPT

As a new user of OpenEMR, I wish to explore its API by sending an authorization request after registering my app and obtaining the client ID and client private key. However, whether I use Swagger or Postman, I encounter an issue where a new page displays the following error message: “error”:“invalid_client”,“error_description”:“Client authentication failed”,“message”:“Client authentication failed”. To rule out any potential problems with my localhost installation, I also tried using three demo servers, namely edu, eleven, and two, but the error persists consistently. How can I resolve this authentication issue?