global $_PLUGINS;

$_PLUGINS->registerFunction('onCPayUserStateChange', 'onCPayUserStateChange', 'LimeSurveyOnPay' );
$_PLUGINS->registerFunction('onBeforeUserProfileDisplay','test','LimeSurveyOnPay');

class LimeSurveyOnPay extends cbTabHandler {

        public function test() {
                error_log("test");  // This works when user profile is shown
        }

        public function onCPayUserStateChange( &$user, $status, $planId, $replacedPlanId, &$integrationParams, $cause, $reason, /** @noinspection PhpUnusedParameterInspection */ $now, &$subscription ) {
            error_log("onCPayUserStateChange");  // This does not work when payment is done
        }

}