1. Download the flashrollbar code or just the <a href="https://github.com/rollbar/flashrollbar/blob/master/build/swc/Rollbar.swc" target="_blank" rel="noopener">Rollbar.swc file.
  2. Place the flash_rollbar/src directory in your source path or place the Rollbar.swc file in your project's library path.
  3. Call Rollbar.init(this, accessToken, environment); from your top-level DisplayObject.
package {
  import com.rollbar.notifier.RollbarNotifier;

  public class MyApp extends Sprite {
    
    public static const ROLLBAR_ACCESS_TOKEN:String = "{{ client_access_token }}";

    public function MyApp() {
      var environment:String = isDebug() ? "development" : "production";
      var person:Object = {id: getUserId(), email: getEmail(), name: getName()};  // optional
      Rollbar.init(this, ROLLBAR_ACCESS_TOKEN, environment, person);
    }
  }
}

Rollbar.init() installed a global error handler, so you don't need to do anything else.