The seller has the opportunity to inspect the goods and should know the law in the country they're exporting to.
That is not how the real world works. If you are buying in China you are doing the transaction under Chinese laws and legal system. The seller is only bound by those and nothing else.
And the same with the other way around. A seller in Europe has no obligation to know the law of the country he is exporting to. Someone buys from him and it is the buyer's responsibility to comply with the laws of the country he is taking it to.
Imagine a European seller who ships a movie, work of literature, wine or food, etc to a country where the item is prohibited. Suppose a court in Booniestan declares the European seller to have broken their laws and imposes a fine. No European country would submit to that and with good reason. It would make trade impossible. And I cannot help but detect a a tone of ethno-superiority in those who say other countries should submit to our rules, presumably because our rules are better, when we would never consider submitting to their rules.
The seller is required to comply with the laws of his own jurisdiction and the importer from another country is required to comply with the laws and regulations of their own jurisdiction. That is the way it is and that is the way it should be. Anything else is just unworkable.
And, from a legal standpoint it does not matter if I bring something with me or if I have it shipped to me. One way or another I am the one who caused the forbidden stuff to move into the forbidden jurisdiction.
A French cheese merchant, a Spanish wine merchant, A Belgian beer seller, etc. only need to comply with the laws of their jurisdiction and they need not know nor care that their product is not legal in some other place.
Buyer buys a product abroad and and when the product gets to customs it is confiscated and destroyed before it enters the country. It is all on the buyer and nothing on the seller.
If there is misrepresentation in the sale then the seller's jurisdiction has jurisdiction unless otherwise agreed. But that is a different matter.