Please garmin connect fix the problem
you cannot change the program when you are out without laptop
You can update the workout in the browser on your phone.
We're pleased to report that this issue has been resolved with the 4.72.1 release of our Connect app, which is available now through your Apple App Store. Please update your Connect app and you'll no longer experience this issue. If you still have issues after updating, please open a new Thread or contact Product Support.