Integration of the Site with 1C through the Exchange Protocol between the system and 1C?

Question

PHP

Once again, good afternoon,
I completed all the stages from the site
. The item "D. Step by step data loading" remains
1C The enterprise must send the file using the post method,
I tried it like that

$filename = $_GET['filename'];
$filename2 = $_FILES[$filename];
//и
$filename = $_GET['filename'];
$filename2 = $_POST[$filename];

But the $filename2 variable is always empty