How do I watch Britbox on my Apple TV now that I subscribed from my ipad

You need to make sure you are manually requesting the code and then add it to the password, if you are trying to enter the password and code all at once it isn’t going to work.

Yes, I know you have an Apple TV box which is why I asked for the model and specified that it was the 3rd Gen. That model does not run apps, all icons are preset and are being accessed from a server. A user cannot add nor delete them. Apple made an update to make a server version of their TV app for it.

It all depends on how you signed up for BritBox on your iPad. If you did so using the TV app then you would access using that on the Apple TV. If you used the Britbox app on iPad then and you don’t have an icon for it on Apple TV then you would have to use airplay to stream from your iPad or cancel that subscription and sign up using the TV app.

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

Did you start this subscription inside the Apple TV app, or in the separate BritBox app, or elsewhere? If you started this subscription inside the Apple TV app, then you will have to watch it inside the Apple TV app. Then that subscription will probably not be available in the dedicated separate BritBox app.

To watch it on your TV, you will need to have either

• an AirPlay-enabled TV and stream it from your iPad;
• or a smart TV with the BritBox app or Apple TV app;
• or a HDMI-connected streaming device with the BritBox app or Apple TV app. This streaming device can be an Apple TV set-top box, or a Roku, or a Fire TV, or select gaming console that allows for these apps.

That is a 3rd gen, which requires signing in differently. You will need to enter the password, then manually request a code and add it to the password.

https://support.apple.com/en-ca/HT204974

Which model Apple TV are you using?