It might be worth checking the phone settings.
Look under " Language & input ".
It will tell you what input methods are installed.
If Stylus Beta is installed it allows you to select it as a possible input.

If it is there, you need to select it when writing. The method is to press and hold in the "text input field". It brings up a symbol in the " Notifications" area, which allows you to pull down a menu to choose it instead of the keyboard.

All this was typed with a finger. The app seems to be Getting Better at recognising my hand writing.
Quack!
GtD.