I came to this thread on almost two weeks ago looking for enlightenment, but only found questions. After an enjoyable laptop-free holiday I'm a little surprised not to see more here, so will add a short report. Apologies if the info is in a different thread and I've missed it.
I am on Android and try as hard as I could, I wasn't able to locate this feature, in the App, after getting the boarding pass. Can you recall how you got to the first screen shot? I am also connecting via LHR, so it may be that my first domestic leg is getting in the way.