How to pop up a modal successful or error after inserted data into database?

Question

I want to produce a pop up modal either success of error message when user inserts data into database. Below I have a form, two modal and php code for insert data from form into database. What I have done, I set sucsess to true to tambahnotisphp.php but it does not do anything.

How can I make pop up modal message after user update data into database. When user input the form and click submit. Then check whether if data successful insert into database, it will pop up succesful modal, but if the data unsuccessful inserted into database it will pop up unsucessful/error modal.

//tambahnotis.php

<script type="text/javascript">
    <?php
        if ($_GET['sucsess'] == 'true'){
            echo '$(document).ready(function() {
                $( "#modal-small" ).dialog();
            });';
        }
    ?>
</script>

<form class="card" action="tambahnotisphp.php" method="post" enctype="multipart/form-data" runat="server" >
    <div class="card-body">
        <div class="mb-3">
            <div class="form-label required">Nombor Fail</div>
            <input type="text" class="form-control" name="nomborFail" id="nomborFail" required="" onkeyup="checkUsername(this.value);">
            <div id="uname_response" ></div>
        </div>
        <div class="mb-3">
            <div class="form-label required">Ulasan</div>
            <textarea class="form-control" id="ulasan" name="ulasan" rows="4" cols="50" required=""></textarea>
        </div>
        <div class="mb-3">
            <div class="form-label required">Tarikh Notis Siasatan Dikeluarkan</div>
            <input type="date" class="form-control" name="tarikhNotisKeluar" id="tarikhNotis1" required=""/>
        </div>

        <div class="card-footer">
            <div class="row align-items-center">
            <div class="col"></div>
                <div class="col-auto">
                    <button type="submit" name="submit" class="btn btn-primary btnTambahNotis">Tambah Notis</button>
                </div>
            </div>
        </div>
    </div>
</form>


<div class="modal modal-blur fade" id="modal-small" tabindex="-1" role="dialog" aria-hidden="true">
      <div class="modal-dialog modal-sm modal-dialog-centered" role="document">
        <div class="modal-content">
          <div class="modal-body">
            <div class="modal-title">Success</div>
            <div>Notis Siasatan berjaya ditambah</div>
          </div>
          <div class="modal-footer">
            <button type="button" class="btn btn-success" data-bs-dismiss="modal">Okay</button>
          </div>
        </div>
      </div>
</div>


<div class="modal modal-blur fade" id="modal-small2" tabindex="-1" role="dialog" aria-hidden="true">
      <div class="modal-dialog modal-sm modal-dialog-centered" role="document">
        <div class="modal-content">
          <div class="modal-body">
            <div class="modal-title">Error</div>
            <div>Notis Siasatan tidak berjaya ditambah</div>
          </div>
          <div class="modal-footer">
            <button type="button" class="btn btn-success" data-bs-dismiss="modal">Okay</button>
          </div>
        </div>
      </div>
</div>

<?php

//tambahnotisphp.php

    include('connection.php');
    $conn=Connect();
    
    $idPengguna = "DI200017";

    $nomborFail = $conn->real_escape_string($_POST['nomborFail']);
    $ulasan = nl2br($_POST['ulasan']);
    $status = "BELUM SELESAI";
    
    $tarikhNotisKeluar = $conn->real_escape_string($_POST['tarikhNotisKeluar']);

    // Add 30 days to the date
    $futureDate30Days = date('Y-m-d',strtotime($tarikhNotisKeluar . ' +30 days'));
    $futureDate60Days = date('Y-m-d',strtotime($tarikhNotisKeluar . ' +60 days'));
    
        
    $query = "INSERT INTO notis(nomborFail, ulasan, tarikhNotisKeluar, tarikhNotis1, tarikhNotis2, status, idPengguna) VALUES('" . $nomborFail . "','" . $ulasan . "','" . $tarikhNotisKeluar . "','" . $futureDate30Days . "','" . $futureDate60Days . "','" . $status . "','" . $idPengguna . "')";

    $success = $conn->query($query);
            
    if ($success){
    header("Location: tambahnotis.php?sucsess=true");       
            
    $conn->close();
    }else{
        die("Data Notis Siasatan tidak dapat ditambah: ".$conn->error);

    }   
    

?>