Harmonica tablature plugin confusion

So I downloaded musescore and this plugin with the ability to convert piano sheet music into harmonica tablature. I have everything working fine except, when I select the plugin it just places a bunch of random x's all over the bars?

(This isn't the tablature I know, and I am ready to fling myself into the sun with the amount of time I have tried to spend converting a single 20 second piano song into harmonica tabs)

Thanks in advance? It is most likely my stupidity, apologies for that.