I bancomat in Bulgaria emettono euro per la prima volta dopo l’adesione all’unione monetaria

That might be the reason Denmark is likely to not accept the euro for a long time.
This nation will go cash less and completely digital currency long before a majority euro referendum will happen.

Euro is legal tender in the member states. You have to accept it being used as a payment form.

A rather difficult starting point, as the number of banks accepting physical money deposits is dwindling, and more and more retailers prefers digital payments.