Culinary weblog The Kitchn notes that this isn't technically a tea but a tisane. Popular tisanes such as chamomile or mint are called herbal teas but that term technically only applies to mixtures of both tea leaves and other herbs.
To make the apple tisane simply simmer a handful of apple peels in a saucepan for five to 10 minutes. This has the side benefit of making your house smell wonderful, particularly if you add a stick of cinnamon.
Got Apple Peels? Make Tea! [The Kitchn]