How to click button in popup window dialog, like following screen shot
If that is a JavaScript alert, you can use these keywords
https://docs.katalon.com/katalon-studio/tutorials/handle_alerts.html
ok. Thank you for you information. Currently I try following method. And it works.
Robot robot = new Robot()
robot.keyPress(KeyEvent.VK_ENTER)
I will use you suggestion in later test scenario.