I have a hand injury that prevents me from using a keyboard or mouse. Luckily, I'm a long time user of magic trackpad even before my injury. However, due to my lack of dexterity, I can no longer perform multi-finger actions. So I'm prevented from using two fingers to scroll up and down, left and right, as well as the pinch, zoom in and zoom out features. I was trying to set up some shortcuts on my Mac to get around this using ChatGPT to talk me through it. ChatGPT suggested downloading better touch tool which I have done but I can't quite work out out to see that. Using my trackpad in conjunction with a modifier key so that when the modifier key is selected, one finger gestures become two finger gestures. Is this possible? And if so, can someone talk me through which settings I need to be working with in order to enable this feature?
Not exactly what you want ... What I was able to accomplish is this:
Click (and release) in the upper right corner of the trackpad and keep your finger on the trackpad = scroll up continuously until the finger is raised.
Click bottom right analog scroll down.
the action is called "send scroll event" (or similar, I have a german system)
activate "key repeat".
Maybe someone knows how to do this better. 
The app "Scroll2" probably does what you want.