extract data from a BD table called note in a shopping cart session for editing

hi greetings I would like to know if someone could help me, what happens is that I am developing an online store in which after saving my shopping cart in my bd, haora was born the need to edit the data of the cart that I keep in the bd, I have been trying to draw the data from my note table with a select and empty them to a session called shopping_cart for its subsequent edition of the list of products and thus update the bd with the new products that the user wants. this is my code I do not load the products to the shopping cart, in which I am wrong greetings I hope you fast, I receive the code of the quote to which this product note is linked by the method get,

<?php
include '../conexion/conexion.php';
$cod_coti=htmlentities($_GET['cod_coti']);
if(isset($_SESSION["shopping_cart"]))
{
  $item_array_id = array_column($_SESSION["shopping_cart"], "item_id");
  // if(!in_array($_GET["cod_coti"], $item_array_id))
  // {

  $sel=$con->prepare("SELECT*FROM nota WHERE cod_cotizacion1 =? ");
  $sel->bind_param('s',$cod_coti);
  $sel->execute();
  $res=$sel->get_result();
  $row=mysqli_num_rows($res);
    while($f=$res->fetch_assoc()){


    $count = count($_SESSION["shopping_cart"]);
    $item_array = array(
      'item_id'         =>   $f['modelo2'],
      'item_name'           =>  $f['nombrepro'],
      'item_price'      =>  $f['precio'],
      'item_quantity'       => $f['cantidad']
    );
    // $_SESSION["shopping_cart"][$count] = $item_array;

    array_push($_SESSION['shopping_cart'], $item_array);
}
    // asigno valor a variable code= a cero para evitar que recarge la pagina con el valor
  // }


}
 ?>

Note the file: include '../conexion/conexion.php'; already contains the sessionstart this is the code in the connection file:

 <?php
    @session_start();//  aqui en sesion start se guardaran todas la variables
    $con= new mysqli('localhost','root','123','empresa');
     ?>