How to prevent the screen from going black when a certain app is running (macOS Sequoia 15.2)

So recently, I downloaded an app from the app store that is a clock that fills the whole screen, but five minutes later, it goes black (because that's the setting I chose on my Mac). I wanted to know if there's a way of preventing the screen from going black when certain apps are running. For example, when that clock app is running, I want it to never go black. This was quite redundant but I think you guys get what I mean, hopefully 😅 Thanks in advance and have a great new year <3