Have apple tv box, apple tv subscription confirmed by email and works on computer but cannot sign in on tv...everything works on tv until I try to put in pw, which apple tv says is incorrect (but it is correct, and is the same as on computer

If you have an Apple TV (2nd or 3rd generation) and two-factor authentication for your Apple ID, then you may be asked to type your password followed by the six-digit verification code directly into the password field. Additionally, there is a time limit, after which the code becomes invalid.

Try this: First enter the characters of your password (do not submit yet), then manually request a new verification code, then append that code to the password (no spaces or other separating characters), and then submit. That should help you get passed the time limit.

What is your model Apple TV box? Identify your Apple TV model - Apple Support