frontend <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title> </head> <body> <form id="frm" enctype="multipart/from-data"> <input type="file" name="upload_file[]" multiple><br><br> <button type="button" onclick="sub();">SUBMIT</button> </form> <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script> <script> function sub(){ var upload = new FormData(frm); console.log(upload); $.ajax({ ...