Error activating Apple TV+ app on iPad with different Apple Account

I have free AppleTV+ access via a Barclays Bank account and have set this up on smart TV on which I can watch programmes. Trying to activate the App on iPad has proved difficult because of a different Apple Account (AA) email. When trying to revert to the same AA as the TV including new passwords and 2 stage verification an Error message always appears so I am still unable to watch/stream on AppleTV+ App on iPad ! Any ideas please to resolve this ?

[Re-Titled by Moderator]

Original Title: AppleTV