How can I use SoapClient in my Php Programm - php

Question

How can I use the SoapClient with the method "sites_web_domain_add" to interact with the ispconfig api? My Code produces a folowing error:
error
Also soap client/server is set to enabled.
If i execute the code in my terminal it just works fine but not in my controller, so have I missed something? Like importing the right soap?
Thanks for helping!
$username = 'apiuser';
$password = '1234';
$soap_location = 'https://localhost:8080/remote/index.php';
$soap_uri = 'https://localhost:8080/remote/';
$context = stream_context_create(
[
'ssl' => [
'verify_peer' => false,
'verify_peer_name' => false,
]
]
);
$client = new SoapClient(
null,
[
'location' => $soap_location,
'uri' => $soap_uri,
'trace' => 1,
'exceptions' => 1,
'stream_context' => $context
]
);
try {
if ($session_id = $client->login($username, $password)) {
echo "Login successful. Session ID: $session_id<br>";
}
//* Set the function parameters.
$client_id = 1;
$params = [
'server_id' => 1,
'ip_address' => '*',
'domain' => 'test2.int',
'type' => 'vhost', // vhost | alias | vhostalias | subdomain | vhostsubdomain
];
$client->sites_web_domain_add($session_id, $client_id, $params, $readonly = false);
if ($client->logout($session_id)) {
echo "Logged out.<br>";
}
} catch (SoapFault $e) {
echo $client->__getLastResponse();
die("SOAP Error: {$e->getMessage()}");
}