I could upload a file using this code :
<!DOCTYPE html>
<html>
<head>
<title>File Upload</title>
<link rel="stylesheet" type="text/css" href="main.css">
</head>
<body>
<h1>File Upload</h1>
<p>Select a new file to upload. Existing files will be
replaced.</p>
<form method="POST" enctype="multipart/form-data">
<input class="button" type="submit" value="Upload">
</form>
</body>
</html>
but despite a choose file button, a get file button, and by pressing it it will download or stream a file from a URL for example :
the file should not appear to the user for saving on the Device, then by pressing the upload button the same process continues