Hello, YAL.  The cheat sheet seems very straight-forward about getting started, but Apollo crashed immediately saying that lua_buffer is not defined when I tried to run lua_add_code().  Poking in the files I found lua_init() but this isn't called by the extension (it is shown as the init function in apollo_core.gml though), nor is it documented on the cheat sheet.  Also, I also get an error on first project reload saying Apollo.yy is missing and had 1 reference.  It might be that newer versions of GM are borking something.  Still, I couldn't find any quick start references or the like, just the cheat sheet, so I'm not sure if I'm just missing an obvious piece of documentation.

EDIT: Immediately after posting this I started thinking: perhaps this function IS called and it's just during the "pragma" phase that it's unavailable and ... yup.  That's it.  If you wait until an object even to run it works fine, but if you try to call the code during an initialization period beforehand, I'm guessing the extension just hasn't called it's init functions yet.  So, issue solved.  It is starting correctly, there's just a period of time when it will crash if called.  The obvious workaround is to clear it from the extension and just call it myself, not sure if that info is helpful to anyone but here it is.