Apple tv is asking for four digit passcode

Do you have the Apple TV box? If so, which model? Identify your Apple TV model - Apple Support

• If you do something that is restricted, then you may be asked for a 4-digit PIN code to override that.
• If you are, or someone else is, trying to use AirPlay from an unpaired device, then you may be asked for a pairing PIN code.
• If you are, or someone else is, trying to pair a mobile device, then you may be asked for a pairing PIN code.

Did you already check the related article mentioned above?

If you're asked to enter an AirPlay password on Apple TV - Apple Support