Converting code from RestSharp to HttpClient

Could someone please help me convert this ASP .Net Core example (to be used in my Web Api to consume a management API from Auth0) which uses RestSharp into one using HttpClient?

var client = new RestClient("https://YOUR_AUTH0_DOMAIN/oauth/token");    var request = new RestRequest(Method.POST);    request.AddHeader("content-type", "application/json");    request.AddParameter("application/json", "{\"grant_type\":\"client_credentials\",\"client_id\": \"YOUR_CLIENT_ID\",\"client_secret\": \"YOUR_CLIENT_SECRET\",\"audience\": \"https://YOUR_AUTH0_DOMAIN/api/v2/\"}", ParameterType.RequestBody);    IRestResponse response = client.Execute(request);

I've been struggling... I've got this:

var client = new HttpClient();
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
client.BaseAddress = new Uri("https://YOUR_AUTH0_DOMAIN/oauth/token");

but I'm not sure about the rest... thank you