How to do countdown

Hello. It would be a question of how to do the countdown. Because no matter how I try / I search I could not find another one that works either.
Thank you in advance for the answer.
Yeah. And I’m sorry for spelling mistakes but Hungarian.

If you mean how to perform an action after a certain amount of time has elapsed, use a timer. If you you mean how to put a countdown on the screen (3,2,1…GO!!) use a text component and alter the text based on a timer. The exact implementation will vary based on what you are actually trying to do.