You can change the Wi-Fi network your Apple TV is connected to, or use network settings on Apple TV and an iPhone or iPad to join a captive Wi-Fi network (such as a hotel Wi-Fi network) that requires sign-in from a browser.
You can also use network settings to switch from a wired network to a wireless network without having to set up Apple TV again.
Go to Settings on Apple TV.
Apple Support article: If your Apple TV can't connect to Wi-Fi