Ok thanks. It sounds like this should be something your payment provider (softcover via proxy through Stripe or whatever they use) would take care of for you.
Other platforms that sell items globally tend to charge EU customers more which probably account for the VAT increase, but in the end gives the author roughly the same amount per sale?
Yes, a lot of sales platforms now handle EU VAT. I've used Gumroad, Sendowl and Leanpub and they all handle the EU VAT problem. In each case the author sets a price. They then detect if the customer is in an EU country and apply the VAT rate for that country, adding it on to the customers total. So the author gets the same amount for each sale, but the customers pay different amounts depending on which country they are in.
Other platforms that sell items globally tend to charge EU customers more which probably account for the VAT increase, but in the end gives the author roughly the same amount per sale?