Triggering onEdit() function in .gs when updating sheet through the app

I looked at the relations tutorial. I will have another look.

I sent you a message with the link to the app.

Right now my friend is running her pie business off a google sheet and the drivers she is working with have to do everything through text and input addresses by hand etc. I am just trying to find a way to automate some of that but they need the functionality of the sheet more than the app right now. Do you know if there is just some way to get the .gs file to run when the app accesses the sheet?

thanks for your help btw.

p