If you're having issues installing your device using the iOS app, make sure your mobile device isn't running iOS 9.3.1. There was an issue with iOS 9.3.1 that affected Bluetooth products of many brands. If that's the OS version you're using, make sure you install a more recent version to fix this issue.
If you still encounter issues, reach out to Customer Service by clicking the Contact us button at the bottom of the page.