NPR Create a new OAuth2 access token

Please be aware that the required parameters are contingent on the `grant_type` that you select. For the `authorization_code` grant type, you are **required** to pass in the `code` and `redirect_uri` parameters. For the `client_credentials` grant type, you do not need to pass in any additional parameters beyond the basic requirements. `code` and `redirect_uri` parameters will be ignored. For the `device_code` grant type, you are **required** to pass in the `code` parameter. If you are a th...