add bootstrap in wordpress file

I was developing a custom form page for the first time. it is on taking review from the customers . I am using the Astra theme.

Bootstrap is not working, and the style function is not functional. When opened on the wordpress local site, everything (form, heading, and even hr tag) appears on the left side.

 <?php
 /* Template Name: Custom Review Page */
 get_header(); // Include header
 ?>

<div id="content">
  <?php
   function enqueue_bootstrap() {
    // Enqueue jQuery first
    wp_enqueue_script('jquery');

    // Enqueue Bootstrap CSS
    wp_enqueue_style('bootstrap-css', 'https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css');

    // Enqueue Bootstrap JavaScript
    wp_enqueue_script('bootstrap-js', 'https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js', array('jquery'), '4.0.0', true);
     }

    add_action('wp_enqueue_scripts', 'enqueue_bootstrap');    

?>
 <div style="text-align: center;">
<h2>Add A Review</h2>
<hr style="border: 0; height: 1px; background: #000; margin: 0 auto;">
 </div>
<div class="container my-5">
    <div class="row">
            <div class="col-12">

 <form method="POST">
<div class="row">
    <div class="col-md-6 col-12">
        <label>Full name</label>
        <input type="text" name="fullname" required>
    </div>
    <div class="col-md-6 col-12">
        <label>Email</label>
        <input type="email" name="email" required>
    </div>
</div>

<div class="row">
    <div class="col-md-6 col-12">
        <label>Country</label>
        <input type="text" name="Country" required>
    </div>
    <div class="col-md-6 col-12">
        <label>Rating</label>
        <input type="text" name="Rating" required>
    </div>
</div>

<div class="col-12">
    <label>Your message</label>
    <textarea name="message"></textarea>
</div>

<div class="col-12">
    <input type="submit" value="Submit" name="submit">
</div>
</form>

</div>
</div>
</div>


 <?php
 if (isset($_POST['submit']))
 {
    $name = sanitize_text_field($_POST['fullname']);
    $email = sanitize_email($_POST['email']);
    $country = sanitize_text_field($_POST['Country']);
    $rating = intval($_POST['Rating']); // Assuming it's an integer.
    $message = sanitize_text_field($_POST['message']);

    global $wpbd;

   // $sql=$wpdb->insert("tablename",array())
    $sql=$wpdb->insert("review_form",array("fullname"=>$name,"email"=>$email,"country"=>$country,"rating"=>$rating,"message"=>$message));

    if($sql==true){
    echo "<script> alert('data inserted') </script>";
    }
    else{
    echo "<script> alert('data not inserted') </script>";
    }
    


}
else{ 
}
?>
</div>

<?php
get_footer(); // Include footer
?>