Posting to an sql database using Unity and PHP

Here is my c# code in unity

  public void addUser()
 {
     WWWForm form = new WWWForm();
     form.AddField("usernamePost", username.text);
     form.AddField("emailPost", email.text);
     form.AddField("passwordPost", password.text);

     using (UnityWebRequest www = UnityWebRequest.Post("localhost/assassin/insertUserData.php", form))
     {
         www.chunkedTransfer = false;
         test(www);
         if (www.isNetworkError || www.isHttpError)
         {
             Debug.Log(www.error);
         }
         else
         {
             Debug.Log("Form upload complete!");
         }
     }
 }
 IEnumerator test(UnityWebRequest www)
 {
     yield return www.SendWebRequest();
 }

Here is my PHP code

 <?php
 $servername = "localhost";
 $server_username = "root";
 $server_password = "root";
 $dbName = "test";
 
 $username = $_POST["usernamePost"];
 $email = $_POST["emailPost"];
 $password = $_POST["passwordPost"];
 
 //make a connection
 $connection = new mysqli($servername, $server_username, $server_password, $dbName);
 echo "hello world";
 //Check the connection
 if(!$connection)
 {
     die("Connection Failed".mysqli_connect_error());
     echo "DEAD";
 }
 
 $sql = "INSERT INTO users (username, email, age, level, lastgame, gameswon, kills, deaths, winnings, password)
 VALUES ('".$username."', '".$email."', '".$level."', '".$lastgame."', '".$gameswon."', '".$kills."', '".$deaths."', '".$winnings"', '".$password."')";
 $result = mysqli_query($connection, $sql);
 
 if(!result)
     echo "There was an error";
 else
     echo "Everything is ok";
 ?>

I get Form upload complete, but when I check my database, no new entry was added