An OAuth 2 access token must be obtained or an exception thrown.

[jay763190097]

I use the example code in readme.md . but it doesn't work.

[funfried]

Same for me, I had to add the grant type "client_credentials" so I was able to get around a 401 Unauthorized response, but now I get:
Unable to obtain a new access token for resource 'null'. The provider manager is not configured to support it.