Do not get AirPlay icon on iPad when away from home network

I brought my Apple TV, iPad, and iPhone to a hotel with me. Although they are all connected to the same wi-if network at the hotel, I do it see the AirPlay icon on either device. How can I mirror my iPad to Apple TV using AirPlay when I am away from my home network? I am attempting to watch a movie that for some reason is not showing up in my purchased movies to watch directly via Apple TV, but is on my iPad.