This information is applicable to all the realme devices.
Taking screenshots by the traditional Volume Down Button + Power Button way is more common and requires a little effort mostly with both hands as well. This sneaky trick will let you take screenshots with three-finger slide on the screen, no need to push any buttons or anything, just swipe the 3 fingers down and you are done.
1. From your Home screen, tap the Application screen icon.
2. Settings -> Smart & Convenient -> Gesture & Motion > enable 3-finger Screenshot slider.