$request_params = array(
'message' => $answer_text,
'random_id' => rand(1, 999999),
'user_id' => $user_id,
'attachment' => 'video-189353548_456239010',
'access_token' => $token,
'v' => '5.103'
);
$get_params = http_build_query($request_params);
file_get_contents("https://api.vk.com/method/messages.send?". $get_params);