How to enable location settings for the app when app is not on the list of location services? The screen above describes situation. Any idea how to turn it on? I have ios 10. 

The app I mean is hostelbookers. It was not happening while ios 9.

Location services for Safari are enabled:



And there is no my hostelbookers app on the list of location services. They are sorted alpha betically.
I tried by opening http://www.hostelbookers.com in a browser. Same pop up shows up. I guess the website is not coded properly. They just made that button but its not probably working. Best alternative is search by entering city name.

Thanks