Cannot find the prime (') key

I live in the USA, and have a standard QWERTY keyboard; I'm running Octave
6.1.0 on a Win 10 computer. I can't find the key to create the prime mark
required to indicate a matrix transpose. Initially, I thought it was the
apostrophe key ('), but that looks different on the screen and Octave does
not accept this for the prime. How do we make this mark?

(I've been simply copying it from previous programs, but that is not a very
satisfactory approach.)

Thanks,
Sam