I've had a letter saying I can now have discovery+ as part of my package. I've managed to activate it on My BT but struggling to download the app. I haven't a clue, technically challenged! Can anyone explain how please.
Unfortunately your TV is too old to support the discovery+ app - it was made in 2014, but needs to be 2017 or newer. You'll need to connect an external device to it - e.g. an Amazon Fire Stick, Apple TV, Roku, etc. You'll also be able to use a BT TV Box Pro very soon.
I can see that you currently have BT TV 4k Recordable box, which is still pretty good. The discovery+ app will be made available on it, however it may be a few weeks as they're still fixing bugs.