GPX tracks while using a common code language (XML) have different elements. Our GPX tracks are formatted to provided information for the iFootpath App and the walks on the App.
We would strongly advise you to follow the route on the App so that you get access to the full walking guide including the detailed walk directions, getting there information, access notes, local history, sound snippets, etc
You can, of course, use the iFootpath App at the same time as your Garmin.
Saying all that, you can use iFootpath GPX tracks on a Garmin - they need a little conversion. Just use the website http://www.gpsvisualizer.com/ upload the file and then output it as a GPX file. The new GPX file should then work with Garmin Base Camp.
You can get the GPX track by logging in then at the top of every walk page you will see a purple icon in the top rightClick or right-click and do a save as.