1.  Download and install from Google Play

(No permissions should be needed or requested).

This is ONLY a keyboard.  You will not see it installed like a normal app in app search!

2. Search "Keyboard" in settings > KeyboardASL > Enable ASL Keyboard.
OR
Go to Settings > System > Keyboard > On-Screen Keyboard > Enable ASL Keyboard.  
OR
Go to Settings > System > Languages & Input > Keyboards > Enable ASL Keyboard.

OR (Android <9)
Go to Settings > Language & Input > Current Keyboard > Choose Keyboards > Enable ASL Keyboard.

3.  (Optional) Press "keyboardASL" to view settings
(Not the enable button.  Press the Text "keyboardASL")

3.  Select keyboardASL as your input method. 

(in some instances you may see a world button)

4. Your ready to type!
Make sure to attach your gif/image before sending.