I can’t log-into Apple TV with Apple ID on Roku.

Is this Apple ID and password functional on any other device? Verify on the Apple ID site.

Or did you recently create a new account?

Also verify the case sensitivity of the password (e.g. 6ChIF2Bp is different from 6cHif2bP or 6chif2bp or 6CHIF2BP).

If the issue persists, then I would suggest to contact an Apple ID expert from the Apple Support staff for further assistance. Contact Apple for support and service (phone numbers) or start your support request online (chat/​email/​callback).

I can’t log-in

Why not? What happens when you try to sign in?