Thanks for the info.
I was working off the ‘API Explorer Application’ quickstart. Was having trouble getting the C# quickstart to work and then the cURL version.
cURL was a GitBash fail when I looked closer, which I resolved.
However, I was struggling for ages with the C# quick start.
For those who come upon it and wonder what the heck (or maybe that was just me) lol…
The RestClient in the quickstart is deprecated. Latest version (107.x) does not use synchronous calls or any of the Header/Parameter settings. Also it no longer will return a IRestResponse.
[https://restsharp.dev/intro.html#introduction]
Below is my working version using async if it helps anyone:
var client = new RestClient("https://YOUR_AUTH0_DOMAIN");
var request = new RestRequest("oauth/token", Method.Post);
request.AddStringBody("{\"client_id\":\"YOUR_CLIENT_ID\",\"client_secret\":\"YOUR_CLIENT_SECRET\",\"audience\":\"https://YOUR_API.eu.auth0.com/api/v2/\",\"grant_type\":\"client_credentials\"}", DataFormat.Json);
var response = await client.ExecuteAsync(request);