I figured out how to add a background image. Go to the web app and edit profile. There’s a button there. Didn’t immediately show up in the Mastodon app on my iPad. I had to edit profile there, then cancel and it was there!
@Cmarrin Well, at least it worked. I haven't tried adding a background image yet but I didn't have a problem with my avatar when I created my account yesterday.
@donmelton yeah, avatars work great, but I couldn’t find a way to add a header from the iPad app.