Message Scratch APP DOES NOT collect any users privacy information for any purpose use. A main feature of Message Scratch APP is to share self Message Scratch to others by showing a QR Code of the Message Scratch. So people can scan the QR Code from my mobile phone and play the Message Scratch at their mobile phone. That's why Message Scratch APP request permission to access camera.
If you don't want/need to use scan QR Code features of Message Scratch APP, you can turn off the permission of Message Scratch APP to access camera in the app settings on your device at any time. Keep in mind turning off the permission of camera may cause Message Scratch APP to lose functionality.