Fatal error: Uncaught PDOException: SQLSTATE[HY093]: Invalid parameter number: number of bound variables does not match number of tokens in php:74 [duplicate]

 if(isset($_POST["create_invoice"]))
  { 
    $sub_total = 0;
    $discount = 0;
    $total_after_discount = 0;

    $statement = $conn->prepare("
      INSERT INTO tbl_medlab 
        (order_no, order_date, order_receiver_name, order_receiver_address, sub_total, discount, total_after_discount,order_datetime)
        VALUES (:order_no, :order_date, :order_receiver_name, :order_receiver_address, :sub_total, :discount, :total_after_discount, :order_datetime)
    ");
    $statement->execute(
      array(
          ':order_no'               =>  trim($_POST["order_no"]),
          ':order_date'             =>  trim($_POST["order_date"]),
          ':order_receiver_name'          =>  trim($_POST["order_receiver_name"]),
          ':order_receiver_address'       =>  trim($_POST["order_receiver_address"]),

          ':sub_total'       =>  $sub_total,
          ':discount'           =>  $discount,
          ':total_after_discount'        =>  $total_after_discount,
          ':order_datetime'           =>  date("Y-m-d")
      )
    );

  $statement = $conn->query("SELECT LAST_INSERT_ID()");
      $order_id = $statement->fetchColumn();

      for($count=0; $count<$_POST["total_item"]; $count++)
      {
        $sub_total = $sub_total + floatval(trim($_POST["order_item_actual_amount"][$count]));


        $discount = $discount + floatval(trim($_POST["discount_amount"][$count]));

        $total_after_discount = $total_after_discount + floatval(trim($_POST["order_item_final_amount"][$count]));

        $statement = $conn->prepare("
          INSERT INTO tbl_medlab_item 
          (order_id,item_type, item_name, order_item_quantity, order_item_price, order_item_actual_amount, discount, discount_amount, order_item_final_amount)
          VALUES (:order_id, :item_type, :item_name, :order_item_quantity, :order_item_price, :order_item_actual_amount, :discount, :discount_amount, :order_item_final_amount)
        ");

        $statement->execute(
          array(
            ':order_id'               =>  $order_id,
            ':item_name'              =>  trim($_POST["item_name"][$count]),
            ':order_item_quantity'          =>  trim($_POST["order_item_quantity"][$count]),
            ':order_item_price'           =>  trim($_POST["order_item_price"][$count]),
            ':order_item_actual_amount'       =>  trim($_POST["order_item_actual_amount"][$count]),

            ':discount'         =>  trim($_POST["discount"][$count]),
            ':discount_amount'       =>  trim($_POST["discount_amount"][$count]),
//ERROR PART START HERE
            ':order_item_final_amount'      =>  trim($_POST["order_item_final_amount"][$count]) 
//ERROR PART END'S HERE
          )
        );
      }
      $total_after_discount = $sub_total - $discount ;

      $statement = $conn->prepare("
        UPDATE tbl_medlab 
        SET sub_total = :sub_total, 
        discount = :discount, 
        total_after_discount = :total_after_discount 
        WHERE order_id = :order_id 
      ");
      $statement->execute(
        array(
          ':sub_total'     =>  $sub_total,
          ':discount'         =>  $discount,
          ':total_after_discount'      =>  $total_after_discount,
          ':order_id'             =>  $order_id
        )
      );
      header("location:md_sale.php");
  }

I am getting an error part on line 74:

Fatal error: Uncaught PDOException: SQLSTATE[HY093]: Invalid parameter number: number of bound variables does not match number of tokens in C:xampphtdocsSanRem MD LABmd_sale.php:74 Stack trace: #0 C:xampphtdocsSanRem MD LABmd_sale.php(74): PDOStatement->execute(Array) #1 {main} thrown in C:xampphtdocsSanRem MD LABmd_sale.php on line 74

I already exhausted all the possible fixes but it is always showing that error.

I was expecting for it to save the data to the database after I click on Create Invoice but then this error show up.