Problem converting PHP file to Prepared statements - php

Question

I'm trying to convert PHP file to Prepared statements. The original file is as follows and it is 100% working before modification:
<?php
include 'connt.php';
$json = file_get_contents('php://input');
$obj = json_decode($json, true);
$Name = $obj['Name'];
$loginQuery = "select * from Users where Name = '$Name' ";
$check = mysqli_fetch_array(mysqli_query($con, $loginQuery));
if ($check) {
$check['result'] = 'Login Matched';
$SuccessMSG = json_encode($check);
echo $SuccessMSG;
} else {
$InvalidMSG = array("result" => "Invalid Username or Password Please Try Again");
$InvalidMSGJSon = json_encode($InvalidMSG);
echo $InvalidMSGJSon;
}
mysqli_close($con);
In the above code, I am checking the data if it matches or not by using the flutter language code:
Future CheckName() async {
setState(() {
visible = true;
});
// var url = 'https://///////////////.php';
var data = {'Name': nameController.text};
var response = await http.post(url, body: json.encode(data));
Map<String, dynamic> message = jsonDecode(response.body);
if (message['result'] == 'Login Matched') {
setState(() {
visible = false;
});
Navigator.push(context, MaterialPageRoute(builder: (context) => Main()));
} else {
setState(() {
visible = false;
});
_showMyDialog();
}
}
Now after modifying the php code as follows:
<?php
include 'connt.php';
$json = file_get_contents('php://input');
$obj = json_decode($json, true);
$Name = $obj['Name'];
$sql = "SELECT * FROM Users WHERE Name=?"; // SQL with parameters
$stmt = $con->prepare($sql);
$stmt->bind_param("s", $Name);
$stmt->execute();
$result = $stmt->get_result(); // get the mysqli result
$user = $result->fetch_assoc(); // fetch data
if ($result) {
$check['result'] = 'Login Matched';
$SuccessMSG = json_encode($check);
echo $SuccessMSG;
} else {
$InvalidMSG = array("result" => "Invalid Username or Password Please Try Again");
$InvalidMSGJSon = json_encode($InvalidMSG);
echo $InvalidMSGJSon;
}
mysqli_close($con);
After modification as above on the code. Now it works, but even if the name is wrong, it works correctly, it does not check if the name is present or not.
How to convert the first file from PHP in a correct way to Prepared statements or can solve the existing error?