M5Stack HTTPS Client with Azure Functions

HTTPSTest.ino

#include <M5Stack.h>
#include <WiFiClientSecure.h>

WiFiClientSecure client;

const char* ssid       = "your SSID";   // WiFi SSID
const char* password   = "your WiFi password";   // WiFi PW
const char* host = "host name (e.g. example.azurewebsites.net)";
const char* path = "url (e.g. /api/EnvMonitor?code=AAA==)";

void setup() {
  M5.begin();
  M5.Lcd.setCursor(0, 0);
  M5.Lcd.setTextColor(WHITE);
  M5.Lcd.setTextSize(2);
  
  if (wifiConnection()) {
    String data = "{\"name\":\"M5Stack\"}";
    Serial.println("POST to https://" + String(host) + path);
    String response = httpsPost(path, data);
    Serial.println(response);
    M5.Lcd.println(response);
  }
}

void loop() {

}

boolean wifiConnection() {
  WiFi.begin(ssid,password);
  int count = 0;
  Serial.print("Waiting for Wi-Fi connection");
  while ( count < 20 ) {
    if (WiFi.status() == WL_CONNECTED) {
      Serial.println();
      Serial.println("Connected!");
      return (true);
    }
    delay(500);
    Serial.print(".");
    count++;
  }
  Serial.println("Timed out.");
  return false;
}

String httpsPost(String url, String data) {
  if (client.connect(host, 443)) {
    client.println("POST " + url + " HTTP/1.1");
    client.println("Host: " + (String)host);
    client.println("User-Agent: M5Stack/1.0");
    client.println("Connection: close");
    client.println("Content-Type: application/json;");
    client.print("Content-Length: ");
    client.println(data.length());
    client.println();
    client.println(data);
    delay(10);
    String response = client.readString();
    client.stop();
    int bodypos =  response.indexOf("\r\n\r\n") + 4;
    return response.substring(bodypos);
  }
  else {
    return "ERROR";
  }
}

run.csx

// for Azure Functions

#r "Newtonsoft.Json"
using System.Net;
using Newtonsoft.Json;

public static async Task<HttpResponseMessage> Run(HttpRequestMessage req, TraceWriter log)
{
    log.Info("C# HTTP trigger function processed a request.");

    dynamic str =  await req.Content.ReadAsStringAsync();
    var obj = JsonConvert.DeserializeObject<Data>(str);
    string name = obj?.name;

    return name == null
        ? req.CreateResponse(HttpStatusCode.BadRequest, "Please pass a name on the query string or in the request body")
        : req.CreateResponse(HttpStatusCode.OK, "Hello " + name);
}

public class Data
{
    public string name { get; set; }
}