Hi there;
The plugin works on at least 10 other themes I have used and just sits in the product data section, however as this is customised on your theme, I think you haven’t included these plugin hooks in the loop.
It’s just a heads-up really, as I’m guessing you will get a few of these and it’s a relatively straight forward fix (evidently I had to do this through creating a child theme and the single-product.php file with the right hooks in, but it’s a shame it’s missing)