I tried that NHS thingy back in January, and spend some time uploading stuff only to be told that they could not verify my identity. The only reason I got the vaccination and booster was to be able to travel - goodness knows, the effectiveness fades soon enough - so this was a little frustrating. The final message was to contact my GP about it. As I haven't visited a GP since 1977, this might not be straightforward as the GP in question is long since dead. So I might have to get around to registering with a GP for the first time in my adult life, merely to get a vaccine passport. Maybe all I need to do is just leave it a bit longer and I won't need one.