Users based outside of the island of Ireland will not be able to watch the games on GAAGO due to rights restrictions in place but can watch them elsewhere.
US-based users can access the games here https://www.dazn.com/en-IE/l/nfl-game-pass/
This article outlines where users based outside of the island of Ireland, US, Canada and China can watch the games https://www.dazn.com/en-US/news/american-football/nfl-game-pass-international-on-dazn-how-to-watch-live-games/214xfjy73nnw1o2olstv9ks5x
For full details on where to watch all upcoming Steelers games outside of the island of Ireland see https://www.steelers.com/schedule/