I'm sorry to throw a spanner in the works but do you realise that the rules for sending stuff to the EU has changed again from 1st July?
If you don't have an EU based intermediary who has registered for IOSS in their country, to do the required paperwork and pay the vat applicable in the recipients country (25% in Croatia, I think?), then when it arrives in Croatia, fees will be applied at customs, plus vat will be charged on the value of the item and on those fees. They will not release the package until that has been paid. If it is not paid, they may return it and charge the sender, adding a further handling charge, or they may destroy it. The fees vary in different EU countries but then tend to have a minimum starting level of about 15€, so a typical example I saw said that an item deemed to be worth 20€ would incur the minimum 15€ fee, then the vat is applied to that total of 35€. (35+25%=43.75).
This doesn't only apply to businesses. It applies to everyone (residing outside of the EU).