There are different ways to deal with the infection. You can cut off the infected parts. Or you can just leave it because it doesn’t kill trees, but it makes plants look strange, especially if the branches are affected. There are also ways to prevent it, like using special sprays or planting apple types that resist the disease.
Overall, this doesn’t harm trees too much! But it’s good to know about it, so you’re ready if it shows up in your backyard! Tell others about it so they can understand this infection too!