Call modal if the condition is met - php

Question

Im trying to make the modal show in the condition is met but the problem is no modal is showing, can someone help me about this? The php code is below of the modal code.
here's the php
<?php
session_start();
include_once("connection.php");
if (isset($_POST['login']))
{
$stud_no = $_POST["stud_no"];
$password = $_POST["pword"];
$name = mysqli_real_escape_string($con, $stud_no);
$password = mysqli_real_escape_string($con, $password);
$select_user = "SELECT * FROM student_accounts WHERE stud_no ='$stud_no' AND password ='$password'";
$run_user = mysqli_query($con, $select_user);
$check_user = mysqli_num_rows($run_user);
if ($check_user > 0)
{
$_SESSION['stud_no'] = $stud_no;
header('location: home.php');
}
else
{
echo '<script>$("#myModal").modal()</script>';
}
}
?>
here's the modal
<div id="myModal" class="modal fade" role="dialog">
<div class="modal-dialog">
<!-- Modal content-->
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal">×</button>
<h4 class="modal-title">Modal Header</h4>
</div>
<div class="modal-body">
<p>Some text in the modal.</p>
</div>
<div class="modal-footer">
<button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
</div>
</div>
</div>
</div>

Answer 1

You just need to INCLUDE jQuery library before PHP code run, as well as bootstrap JS. And see the results, it will worked.
IF still not worked use below code to echo your script::
echo '<script type="text/javascript">'
. '$( document ).ready(function() {'
. '$("#myModal").modal("show");'
. '});'
. '</script>';

Answer 2

Replace below line
echo '<script>$("#myModal").modal()</script>';
with
echo '<script>$("#myModal").modal('show')</script>';

Answer 3

First include JQUERY CDN in the tags
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
if (condition === true) //Strict comparison
$(document).ready(function(){
$('#form').modal('show');
});
else
......
N/B #form is the ID for the modal