How to upload multiple files to a PHP file - php

Question

I am currently creating this code for a website. I have this file upload working but I am needing to upload multiple files instead of one. I don't know the best way to do this with my current code. Any help is appreciated.
<?php
include "DbConnect.php";
$db = new DbConnect();
$conn = $db->connect();
//INSERT INTO account(AccountID, Username, Password, LastName, FirstName, Accountemail, phone) values(1, 'dsf', 'sdf', 'sdf','df','dsf', '')
$sql="INSERT INTO Product(sku, ItemName, ItemDescription, Quantity, PostDate, ItemPrice,
Accountemail, Category, Image) values(".$_POST["sku_no"].", '".$_POST["item_name"]."', '".$_POST["item_desc"]."',".$_POST["qty"].",'".$_POST["date_of_sale"]."', ".$_POST["price"].", '".$_POST["Accountemail"]."', '".$_POST["category"]."','')";
// Loop through each file
if ($conn->query($sql)) {
$photo = $_FILES["file"];
$filename = '';
if (!file_exists("images")) {
mkdir("images", 0777, true);
}
$filename = time().'_'. $photo['name'];
$file = "images/" . $filename;
$thumb_image = $photo;
if (move_uploaded_file($photo['tmp_name'], $file)) {
$sql_query = "UPDATE Product SET Image = '".$filename."' WHERE ProductID = $conn->insert_id";
$stmt = $conn->prepare($sql_query);
$stmt->execute();
$stmt->close();
}
$data = array(
'message' => "Product added successfully",
'success'=>"1"
);
//redirect to questionnaire page
//echo 0;
//echo $data;
echo json_encode($data);
}else{
$data = array(
'message' => "Product not added",
'success'=>"0"
);
echo json_encode($data);
}
?>