Steps

1. Install the legit version for free
2. Uninstall the legit version
3. Download from Rookie and install like normal (wait for Success message)
4. Turn off your Quest Wifi
5. Launch Epic Roller Coasters
6. It will attempt a sync, fail, and then you need to click on "Launch App"

Optional: you can turn wifi back on now.

7. Click a ride's download button, and then cancel to get the "alternate server" version.  That is the one you click on.