Query not inputting data into the database using Unity Engine, C#, SQL, and PHP

I was bored and messing around doing random tutorials like I do. Stumbled onto a Unity and MySQL tutorial that basically went into making a basic database for storing login data for users. I thought it was interesting and went along with it and seemed to have no issues until it came together in the most base form. Only issue is no entry is made in the database.

C# Code

using System.Collections;
using System.Collections.Generic;
using TMPro;
using UnityEngine;
using UnityEngine.Networking;
using UnityEngine.UI;
//using static UnityEngine.Rendering.DebugUI;

public class Registration : MonoBehaviour
{

    public MainMenu mainMenu;

    public TMP_InputField nameField;
    public TMP_InputField passwordField;
    public TMP_InputField confPasswordField;
    public TextMeshProUGUI errorField;

    public Button registerButton;

    public void CallRegister()
    {
        StartCoroutine(Register());
        Debug.Log(nameField.text);
        Debug.Log(passwordField.text);
    }

    IEnumerator Register()
    {
        WWWForm form = new WWWForm();
        form.AddField("Username", nameField.text);
        form.AddField("Password", passwordField.text);
        using (UnityWebRequest www = UnityWebRequest.Post("http://localhost/sqlconnect/register.php", form))
        {
            yield return www.SendWebRequest();
            if (www.result != UnityWebRequest.Result.Success)
            {
                Debug.Log(www.downloadHandler.text);
                mainMenu.GoToMenu();
            }
            else
            {
                Debug.Log("User Creation Failed. Error #" + www.result);
                errorField.text = ("User Creation Failed. Error #" + www.result);
            }

            www.Dispose();
        }

    }

    public void VerifyInputs()
    {
        registerButton.interactable = (nameField.text.Length >= 8 && passwordField.text.Length >= 8 && confPasswordField.text == passwordField.text);
    }

}

PHP Code

<?php

    $con = mysqli_connect('localhost', 'root', 'root', 'mantleonline');

    //Check connection occured
    if(mysqli_connect_errno())
    {
        echo "1: Connection Failed"; //Error Code #1 = Connection Failed
        exit();
    }

    $username = mysqli_real_escape_string($con, $_POST['Username']);
    $password = mysqli_real_escape_string($con, $_POST['Password']);

    //Check if username unique
    $namecheckquery = "SELECT username FROM players WHERE username='" . $username . "';";

    $namecheck = mysqli_query($con, $namecheckquery) or die("2: Name Check Query Failed") //Error Code #2 = Username Query Check Fail

    if(mysqli_num_rows($namecheck) > 0)
    {
        die("3: Name Already Taken"); //Error Code #3 = Username not unique. Cannot register.
    }

    if(mysqli_num_rows($namecheck) < 0)
    {
        echo "69: Bullshit"; //Error Code #3 = Username not unique. Cannot register.
    }

    //Add user to table
    $salt = "$5$rounds=5000$" . "eternull" . $username . "$";
    $hash = crypt($password, $salt);

    $insertuserquery = "INSERT INTO players (username, hash, salt) VALUES ('". $username . "', '". $hash ."', '" . $salt . "');";
    $mysqli_query($con, $insertuserquery) or die("4: Insert Player Data Query Failed"); //Error Code #4: Insert Player Data Query Failed

    echo("0");

?>

I’ve tried stitching in what I could learn from a few other places such as swapping from Unity’s WWW to UnityWebRequest. Honestly I suspect that the error springs somewhere within there as I am not receiving any error messages on running, but I wouldn’t be surprised if I’m just saving these values and then dumping them or not passing them along somewhere and thus running blank queries every time.