I created a SOAP client like so:
$client = new SoapClient(\"file.wsdl\");
And then when I want to call an API function
$client-
$info = $client->__call("myAction", ['body' => ['param1' => '123', 'param2' => '456']]);
$client = new SoapClient("your wsdl file");
$stock = "NCR";
$parameters= array("request"=>$stock);
$values = $client->someMethod($parameters);
it all depends on how the soap server defines,parameters can be string and array as you like.your problem is paras not legal previously,check the wsdl file or the soap server.
you should pass an array for the parameters and give your parameters names (those can be found in the wsdl-file). in your case, the result should look like this (assuming the parameter-names should be param1
and param2
on the basis of the error-message):
$client->Authenticate(array('param1'=>"user", 'param2'=>"password"));