<?php
$cmd = array(
    "message" => array(
	"action" => "keres_tel",
	"apikey" => "APIKULCS",
	"request" => array(
	    "params" => array(
		"tel" => "36201234567"
	    )
	)
    )
);
$url = "https://api.netfizetes.hu/api.php";
$options = array(
  'http' => array(
    'method'  => 'POST',
    'content' => json_encode( $cmd ),
    'header'=>  "Content-Type: application/json\r\n" .
                "Accept: application/json\r\n"
    )
);

$context  = stream_context_create( $options );
$result = file_get_contents( $url, false, $context );
$response = json_decode( $result );
print_r($response);

?>