Hi there and happy new year!
Not that it's not easy to find this information but I recently signed up on Snapchat and let's be honest, it's not easy to capture the device screen when long tapping the screen.
Fortunately, Android development kit comes with a shell that allows to control your device from your computer through adb. No teaching you anything today.
I quickly wrote a tiny script that would allow anyone who found the way to install adb to capture your device screen remotely.
Create a screenshot file in the same folder of the adb binary and paste