Hotel internet connections often require you jump through a few hoops before you get connected.
They have a step during the wifi connection process called "captive portal". It's a pop-up screen that usually requires you to enter your last name and room number before you get connected. Sometimes its just a button that you need to click. Sometimes it's something else.
This is fine if you're on a phone or laptop. But AppleTV doesn't let you enter this information.
Here's how to bypass this "captive portal" nonsense.
First, you must have an Apple laptop.
Second, get your AppleTV connected to the hotel TV on the HDMI, and make sure its plugged into the power outlet. Get AppleTV accessible on the Hotel TV. You may have to figure this out, most likely changing the input settings on the TV.
Third, once AppleTV is accessible on the hotel TV, navigate to:
Settings > Network
** Do not connect to the hotel wifi yet. **
Look for the "Wi-Fi MAC address" at the bottom of the screen. It will look something like this:
64:d2:c4:a2:c0:a8
Write it down because you will need it later.
Fourth, now we will "spoof" the Apple TV's MAC address.
On your laptop, open a Terminal window. (Command + Spacebar, then type terminal)
Paste this into terminal:
sudo ifconfig en0 lladdr <your appletv Mac address>
It will look similar to this:
sudo ifconfig en0 lladdr 64:d2:c4:a2:c0:a8
It will ask you to enter your laptop admin password. Do that and hit return. There will not be any output. That command set your laptop MAC address to your AppleTV MAC address. That's the "spoof".
Now, on your laptop, click on the wifi icon in the top bar, and connect to the hotel wifi. Enter your info (usually your last name and room number) and connect to the hotel wifi.
Fifth, we need to change the laptop MAC address back to its original. Put this command into Terminal and hit return.
sudo ifconfig en0 lladdr \ > $(networksetup -getmacaddress en0 | awk '{print $3}')
Sixth, in your AppleTV, go to:
Settings > Network > Wifi
Connect to the same hotel wifi network that you just connected to on your laptop.
You should be good to go.
If it doesn't work, "forget network" from AppleTV and your laptop. Then unplug and replug your AppleTV from its power source. Restart your laptop. Try this process again.