You can use the Get Games endpoint https://dev.twitch.tv/docs/api/reference#get-games and specify up to 100 game ids with the game_id querystring param and the game id that you got from the Get Streams endpoint.
As games infrequently update, it’s common to create a cache on your end so that you’re not constantly looking up what game 33214 is, if you already know it’s Fortnite.