ช่วยทีครับอัปเดทข้อมูลแล้วมันไม่เปลี่ยนแปลง ต้องแก้ยังไงครับ

<?php 
    ini_set('display_errors', 1);
    ini_set('display_startup_errors', 1);
    error_reporting(E_ALL);
session_start();
if(isset($_REQUEST['submit'])){

include("connect_db.php");

$people_member = $_REQUEST['people_member'];
$people_talent =  $_REQUEST['people_talent'] ;

$sql="update tbl_p set people_talent = '$people_talent' where people_member ='$people_member' ";      
    $result = mysqli_query($con,$sql) or die ("Error in query: $sql " . mysqli_error()); 
   
if ($result){
 echo "<script>";
echo "alert(\" แก้ไขข้อมูลสำเร็จ\");"; 
echo "window.history.back()";
echo "</script>";

} else  {    
      echo "เกิดข้อผิดพลาด " ;   
}
 mysqli_close($con);
 } 

<form class="user"  method="POST" action="people_update_db.php" >
                         <div class="form-group row">
                         <div class="col-sm-6 mb-3 mb-sm-0">
                             <input  id="people_memmber" name="people_member" type="hidden" class="form-control form-control-user" id="exampleFirstName" value="<?php echo $_SESSION["people_member"]; ?>" >
                        
               
                 <div class="form-group row">
                  <div class="col-sm-6 mb-3 mb-sm-0">
                    <input name="people_talent" type="text" class="form-control form-control-user" id="exampleInputPassword"  placeholder="ความสามารถพิเศษ" value="<?php  echo $_SESSION["people_talent"]; ?>">
                  </div>
    
                         <button   type="submit"class="btn btn-primary btn-user btn-block">
                  บันทึก
                         </button>
                <hr>
               
              </form>