There is no automatic setup available for Flash.
There is generally no setup required for the Flash target, but you will want to have a "Content Debugger" version of the standalone Flash Player on your system, configured as the default application for *.swf files:
It can be difficult to install the standalone player when running Linux, so here another resource that can help for automatically configuring it for a Gnome-based distribution:
If you encounter any problems when setting up OpenFL for Flash, please visit the forums.