Difficulty mirroring iPad to Apple TV

I'm trying to mirror my iPad screen on my Apple 4K TV. I bring up control center on the iPad and tap AirPlay and then Apple TV. The iPad then asks for a password for the Apple TV while the Apple TV displays a four-digit passcode. One wants a password while the other is giving a passcode. What gives? Entering the passcode does not work. I don't know what it means by Apple TV password. I don't use a password on my Apple TV. Entering my iTunes password, assuming that this is what the iPad means when it asks for my Apple TV password, does not work. I've even appended the four-digit code to the end of my iTunes password and that does not work either. Any advice?