specify harmonica key & which position (1st/straight, 2d/cross, 3d/slant)?

I'm brand new to MuseScore. I just imported a Guitar Pro 7 guitar file and want to transpose to and generate harmonica tabs, after installing the harmonica plugin. I don't really read standard notation and am quite disoriented by the results, which include a lot of X marks, which I assume means the notes are outside the range of the specified diatonic harmonica. It would help if I could make sure that the tab is for the harmonica I'm using in the position I'm using. Specifically, I want to use a C harmonica in 2d position, which is actually the key of G. I don't see a way to specify that with the harmonica plugin. Is it possible to do so somehow?