Route call wrong method

I found another weird issue, I have this route:



if I call it using:

PHP Code:

url: `<?= route_to('admin/media/files') ?>/${$(this).attr('data-id')}/details` 


in $.ajax, I wil get only "${$(this).attr('data-id')}/details`", so actually route_to return an empty value. But if I do:

PHP Code:

url: `<?= base_url() ?>/admin/media/files/${$(this).attr('data-id')}/details`, 


I get the correct url, why route_to is returning me an empty value?