After Star Wars Battlefront 2 was given away by Epic, the servers crashed

Star Wars Battlefront 2 is currently available for free on the Epic Games Store, but you might have trouble playing anything other than the singleplayer modes. Players have been seeing error codes 623, 918, and 721, all of which point to the same problem—no connection to EA’s servers.

EA has been working to fix the problem, as the EA Help Twitter account explained: “An incredible number of players have joined us during our @EpicGames Store free week and we’re scaling up new servers to welcome you all to the Battlefront.” 

source: gamezpot.com