I believe the issue is not with OP or with iPad rather it is that canvasGUI does not process touch events.
I created canvasGUI because I wanted to learn JavaScript and I wanted a meaty project to get my teeth into. Unfortunately I have no experience programming touch events and I had enough to get to grips with including VSC, TypeScript, p5js, WEBGL, Typedoc, GCC and of course JavaScript so touch events got put on the back burner.
Perhaps it is time for me to revisit canvasGUI and touch events but I have had other exciting projects demanding my attention. 