Space at the beginning of Laravel xml output, where does it come from?

Question

Laravel

I connect Yandex.Checkout payment to the site on Laravel.
When checking the payment, you need to return the response in xml. I return as follows:

$contents = '<?xml version="1.0" encoding="UTF-8"?><checkOrderResponse performedDatetime="'.date('c').'" code="0" invoiceId="123" shopId="123"/>';
$response = Response::make($contents, 200);
$response->header('Content-Type', 'text/xml');
return $response;

An incomprehensible space appears at the beginning of the file. As a result, the answer is not accepted.
Please help me figure out where and at what stage it appears there.

Answer 1

By chance this is not BOM?