Most of the stuff I read and write has these, and normally, it's fine. But here are some stuff you should take into consideration when you're writing these.

-Make them short. ANs should be at maximum, 1/5 of the rest of the chapter.

-Make then focused. Don't go rambling off about something that happened in your life for no reason. We're here for the story, not your personal drama. If you're going to write an AN, it should be something relating to the story itself.

-Don't make entire chapters for ANs. I was guilty of doing this in one of my first Wattpad books a few times. Attach them to the end of the last chapter or the next thing you know, half your chapter counts are comprised entirely of ANs. That's not good. The only reason you should make entire AN chapters is either as a greeting to your audience, a farewell to your audience, or after your entire story has ended and you've hit a milestone (reads or votes). Other than those cases, avoid AN chapters.

So... yeah!