Apple TV update failed, device stuck in boot loop

I turned on my Apple TV, and the TV box and phone appeared on the screen. I placed the phone next to the box. Two buttons appeared on the phone: update Apple TV and reboot. I clicked update. The download started and then immediately stopped, saying the update was incomplete and to try again later. The window on the phone closed. I tried rebooting the box. The light on the Apple TV started blinking, the Apple logo appeared on the screen and disappeared, then appeared again and disappeared again, and the indicator light blinked endlessly. I understand that the firmware has crashed. What should I do?