title: BB2.21.4 Export issue: Undefined symbols for architecture arm64
body: <p>I made an app with Buildbox (I’m using Facebook Audience Network), but when I opened the app in Xcode to start uploading, this errors appeared !
  Please any help or suggestions to fix this ?</p>
  <p>(See image bellow)</p>
  <p><a href="https://i.stack.imgur.com/4DaJK.png" rel="nofollow noreferrer">Attached file</a></p>