How do I set up a function app to extract data fro

I have the following code in my Function App

using System.Net;

public static async Task<HttpResponseMessage> Run(HttpRequestMessage req, TraceWriter log)
{
   var data = await req.Content.ReadAsAsync<PostData>();

   var sid = data.sid;

   log.Info($"sid ={sid}");
   return req.CreateResponse(HttpStatusCode.OK, $"Current Time : {DateTime.Now}"); 
}

public class PostData 
{
   public string sid { get; set; }
}

The error message is

No MediaTypeFormatter is available to read an object of type 'PostData' from content with media type 'application/x-www-form-urlencoded'.

How do I set the function up to work with the correct media type?

[Update]

If I change the code to

var content = req.Content;
var jsonContent = await content.ReadAsStringAsync();
log.Info(jsonContent);

I can see the jsonContent text logged starting with

ToCountry=AU&ToState=&SmsMessageSid=SM8cac6c6a851  etc

But I am unclear on how to go about extracting the data I need.

I tried adding

 dynamic results = JsonConvert.DeserializeObject<dynamic>(jsonContent);

and

using Newtonsoft.Json;

however this causes a script compilation error

[Update] Studying the sample code on the Integration Tab

Example C# code for a GitHub WebHook function

#r "Newtonsoft.Json"

using System;
using System.Net;
using System.Threading.Tasks;
using Newtonsoft.Json;

public static async Task<object> Run(HttpRequestMessage req, TraceWriter log)
{
    string jsonContent = await req.Content.ReadAsStringAsync();
    log.Info("Hi 1");   // does log
    dynamic data = JsonConvert.DeserializeObject(jsonContent);

    log.Info("Hi 2");  // does not log

    return req.CreateResponse(HttpStatusCode.OK, $"Current Time : {DateTime.Now}"
    });
}

This produces an error

System.AggregateException : One or more errors occurred. ---> Unexpected character encountered while parsing value: T. Path '', line 0, position 0.
   at Microsoft.Azure.WebJobs.Script.Description.DotNetFunctionInvoker.GetTaskResult(Task task)

For application/x-www-form-urlencoded, the body of the HTTP message sent to the server is essentially one giant query string -- name/value pairs are separated by the ampersand (&), and names are separated from values by the equals symbol (=). An example of this would be:

MyVariableOne=ValueOne&MyVariableTwo=ValueTwo

We could get more info about application/x-www-form-urlencoded from another SO thread.

Currently, not all of the various ASP.NET WebHook receivers are handled fully yet in Functions. I also find a smilar SO Thread. Azure Functions can support 3 types of webhooks: Generic JSON,GitHub,Slack. But we could handle it with our logic. You could have a try to use the following code to get the key value in the Dictionary.

 Dictionary<string, string> myDictionary = new Dictionary<string, string>();
 if (req.Content.Headers.ContentType.ToString().ToLower().Equals("application/x-www-form-urlencoded"))
  {
      var body = req.Content.ReadAsStringAsync().Result;
      var array = body.Split('&');
      foreach (var item in array)
      {
            var keyvalue = item.Split('=');
            myDictionary.Add(keyvalue[0],keyvalue[1]);
       }

  }
 var sid = myDictionary["SmsMessageSid"];
 log.Info($"sid ={sid}");
 return req.CreateResponse(HttpStatusCode.OK, $"Current Time : {DateTime.Now}");