Hello Kalin,
We regret to inform you that the filter widgets are only designed to work on Shop/Category pages, where they can sort out the results from all available products. As there are no products to sort out on a single product page, these widgets cannot be used there. If you wish to use the filter widgets on a single product page, we suggest you look into third-party plugins that may better meet your requirements.
Thank you for your understanding.
Best Regards,
8Theme’s Team