Delay display clock

im doing a project where you can open chest box and i want user to wait 30 seconds before opening again and i want to do notifier alert how much he need to wait

Use a clock timer
Set the interval you want - e.g. 30 seconds (30000ms)
Start the clock when user opens chestbox
Display the alert (or use a progress dialog)
In the Clock Timer event block:
Stop the clock
Do any other action
(close the progress dialog if used)