Hi John,

Thanks for getting in touch!

B2BKing doesn't have a built-in feature for downloading products as PDFs directly. 

For a plugin recommendation, I don't have extensive experience with PDF attachment plugins, but I did a quick search and found this article that might be helpful: https://barn2.com/blog/woocommerce-attach-pdf-to-product/ 

Barn2 is a good company and I'd feel confident recommending their plugins if the functionality matches what you're looking for.

Kind regards,  
Stefan