I would caution using copper products or harsher treatments, like with many scaleless/sensitive fish. Methylene blue baths are something they tolerate well and clear up fungus and bacterial infections if you encounter those in the future.
Praziquantel treatments are tolerated without problem (internal parasites). Also Diflubenzurone (dimilin for external parasites- anchor worms or fish lice) are on the safe list. You can use praziquantel to be on the safe side if you feel the need during quarantine. You'll see visual evidence if Diflubenzurone or MB bath is needed.
What kind of lungfish is it? Share some pictures with us pretty please?