It's even worse than that in terms of correctness, because the author confuses the EU ( economic and political bloc), Europe ( the continent) and the eurozone ( countries in a monetary union with the single currency, euro). SEPA is a thing for euro-denominated transfers in the EU and some extra countries ( UK, Norway, etc.).

Belarus, a country in Europe, but outside the EU and eurozone, aren't in SEPA . Romania, inside the EU but not in the eurozone, are in SEPA. Montenegro are outside of the EU and eurozone, use the euro, but aren't in SEPA.