"Optimum" being a cable tv package where your paid subscription provides TBS?
The Watch TBS app only works for those who have authenticated they are paying for it via a paid "tv provider" account that includes TBS access.
From within the Watch TBS channel app on your Roku, click on the SIGN IN item in the upper right corner.
Then under "SIGN IN WITH YOUR TV PROVIDER" click on the orange SIGN IN box. Follow the prompts to log in via your Optimum credentials.
Note: if you are ALREADY signed in with your Optimum credentials (no SIGN IN link in upper right) click on the little head-and-shoulders icon and try signing out then back in.
Roku Community Streaming Expert I am not a Roku employee, only a user like you. Please, no support questions via private message -- post them publicly to the Community where others may benefit as well. If this post solves your problem please help others find this answer by clicking "Accept as Solution.".
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