I followed the code example at https://developers.ringcentral.com/guide/voice/ringout#c# but getting error 400 on the "Authorize" line.
One or more errors occurred. (Call failed with status code 400 (Bad Request): POST https://platform.devtest.ringcentral.com/restapi/oauth/token).
Here is code:
static RestClient restClient;
static void Main(string args)
restClient = new RestClient("client-id",
Can you tell me what did I do wrong?