Insert countdown in event category templates

Hello.
I have created a template for event categories but I don’t see where to add the countdown to make it work.
When choosing the countdown, it stays at 0 days 0 hours and 0 minutes because it does not “connect” with the date of the event.
I’ve seen that you’ve already been asked this question, but I can’t find it because your website’s search engine doesn’t work. And I don’t know what you answered :-).
Can you help me?
Thank you!!