Hier ein Beispiel, wie man einen Request absetzt.

Die Funktion curlSend() setzen wir in allen weiteren Beispielen als vorhanden voraus.

<?php
header( "Content-Type: text/plain; charset=UTF-8" );
$pre_data = new stdClass;

$UpdateParams = array (
    "dataUser" => array (
        'token' => '****************',
    ),
    "content"  => array (
            'find' => array (
                array (),
            ),
        ),
    )
);

$url = 'https://client.pdf-box.de/interface.php';

$response = curlSend( json_encode( $UpdateParams ), $url );

$data = json_decode( $response, true );

var_export( $data );

function curlSend( $content, $url )
{
    $headers = array ( "POST " . dirname( parse_url($url, PHP_URL_PATH) ) . " HTTP/1.0",
        "Content-type: application/json;charset=\"utf-8\"",
        "Accept: application/json",
        "Cache-Control: no-cache",
        "Pragma: no-cache",
        "Content-length: " . strlen( $content )
    );

    $ch = curl_init();
    curl_setopt( $ch, CURLOPT_URL, $url );
    curl_setopt( $ch, CURLOPT_RETURNTRANSFER, 1 );
    curl_setopt( $ch, CURLOPT_TIMEOUT, 60 );
    curl_setopt( $ch, CURLOPT_HTTPHEADER, $headers );
    # curl_setopt( $ch, CURLOPT_USERAGENT, $defined_vars['HTTP_USER_AGENT'] );

    curl_setopt( $ch, CURLOPT_SSL_VERIFYPEER, false );
    curl_setopt( $ch, CURLOPT_SSL_VERIFYHOST, 2 );
    curl_setopt( $ch, CURLOPT_POST, 1 );
    curl_setopt( $ch, CURLOPT_POSTFIELDS, $content );

    $data = curl_exec( $ch );

    if ( curl_errno( $ch ) ) {
        print "Error: " . curl_error( $ch );

        return 'Fail';
    } else {
        curl_close( $ch );

        return $data;
    }
}