As far as I know, it seems to be exclusively used to mean similar to 'must, or have to'. But can it be used to express "an opportunity of the past" in British English? as in
I have got to meet all the stars once before.
I think in American English its problem can be easily solved by writing 'gotten' instead of 'got', but when it comes to BE, I don't figure out how to remove the ambiguity.