How to "wakeup" my Raspberry program by 7" RPI screen touch event without full screen black "button"


I am new here and unfamiliar with Markdown so please bear with me.

When my Raspberry Pi4 program is idle for some, I turn the RPI 7" display black as standby mode.

This is what I try to achieve:
How to “wake-up” from “standby” (via callback) by tapping the display anywhere without having a dummy full black screen graphic “button” ?

Thank you,