In the file inc_php/unitecreator_web_api.class.php find the function callAPI and change line 399 from this:
$data["domain"] = GlobalsUC::$current_host;
to this:
$data["domain"] = "google.com";
Now find the function activateProductFromData which starts around line 524. Just before this line of code:
$responseAPI = $this->callAPI("activate", $reqData);
add this:
$this->saveActivatedProduct($code, ''); return('1024');
Now use any key to activate the plugin and all the Pro modules will be available.