Step 5.7 Get New Access Token fails with Error: unauthorised_client: Unknown client or client not enabled

[craigvantonder]

OS: Ubuntu 18.04.5
Postman: v8.2.3

When following the official documentation step 5.7 does not produce the login screen as is indicated, it fails with:

Any input on this would be greatly appreciated.

[musabibnusiraj]

I faced the same error.
Check client id & client secret.

Works fine now ☺️