Oh this is fantastic! We no longer need to log into the app to precondition. I really wish they would offer integration with Siri, but this is a big help.
Assuming you already have the Mini app installed on your iPhone - on your phone's home screen, swipe your finger to the right. This should show the widget screen.
Touch the "edit" button
Touch the "+" button
Scroll down to the Mini app, touch it, and then "add widget"
This is on IOS 16 beta, but I think it's pretty much the same as prior versions. You have to be on at least IOS 14.