Inside of BigCommerce, navigate to your products section from the Admin panel. In your ALL Products view click into edit the product you wish to exclude.
At the top of the Navigation for editing the product details, you will need to click Other Details.
Inside of Other Details there is an input for search keywords. You can insert 'fomo-ignore' there.
And then click to 'save' this settings change.
Back inside the Fomo Admin dashboard, toggle your Event threshold to + or - 1 day. And this will trigger a new import of orders, excluding the products that have been labeled with 'fomo-ignore'.