Onyx has their own clicker, like a TV remote.
I prefer something smaller, see this thread:
https://www.mobileread.com/forums/sh...d.php?t=341684
The problem with a mouse, is that it will be identified as a mouse. Shocking, eh?
That means it will put a little arrow on the screen. It might disappear after a while.
The cheapest one button "selfie" clicker might work and might be good enough for you, or not.
They usually send something stupid, like Volume Up.
Your reader app may process that or you might be able to mod the app too.