Aperol is a brand, and both "Aperol" and "Aperol Spritz" are trademarked.
Painting the drink is completely fine, and so is being inspired by it. Where artists get into trouble is putting the brand name in the title or the keywords, because at that point you're using someone else's trademark to help sell your own product.
Print-on-demand sites will pull listings over it, and licensing clients don't want that risk attached to artwork either.
So I described the drink instead. "Orange Fizz Cocktail" tells people exactly what they're looking at while covering my bases legally.
Just a tip to always check on that kind of thing before naming your work and setting up your product listings. It'll save you a bunch of headache in the long run!