You need to enter the lounge with your CAC (Common Access Card).
The American Airlines lounge is free if you have JAL Global; otherwise, it costs about $65.
The lounge is accessible if you have British Airways silver or gold status or a lounge pass.
I have been using it now for 3 months and it saves me so much research. Reduces the need to call and double check every time.
How did I not know these places existed?! Atly's scoring is a lifesaver, now I can finally find THE spot without wasting time Googling my life away.