wp_remote_post help

Hey guys

I know that it shouldn’t be as hard as it is but I can’t get it to work somehow. I know that it may be easy to fix but I just started to learn all of this and yeah. Gotta teach myself all of that.
What I created so far is the link in order to retrieve the code.
After that I’ve got to get a request from api.twitch.tv/kraken/oauth2/token but it doesn’t work somehow. What did I do wrong?

<?php

$usercode = $_GET['code'];

$args = array(
	'method' => 'POST',
	'body' => 'client_id=91th8b4i2ouxdfn660xojhu1eqfaonu&client_secret=dqhzi4h2k2rnb67bzbno9kva43uwmf9&grant_type=authorization_code&redirect_uri=https://decimo.net/token.php&code=', $usercode);

$answer = wp_remote_post('https://api.twitch.tv/kraken/oauth2/token', $args);
if( is_wp_error( $answer ) ) {
   $error_message = $answer->get_error_message();
   echo "Something went wrong: $error_message";
} else {
   echo 'Response:<pre>';
   print_r( $answer );
   echo '</pre>';
}
?>

I just get a blank page. Is it maybe because I put the file @root of WP-folder?

Thanks a lot