Bethesda has indeed confirmed Fallout 5, but since it is in the queue after Starfield and The Elder Scrolls VI, we can of course expect that it will be many years before it is released.
In the meantime we can play Fallout 3 or we can wait for the current-gen upgrade of Fallout 4, which will be released sometime in 2023 for Playstation 5, Xbox Series X|S and PC. Bethesda reveals it in connection with Fallout’s ongoing 25th anniversary celebration.
Prepare for the future: A next-gen update is coming to Fallout 4! Coming in 2023, this free update will be available for Xbox Series X|S, PlayStation 5 and Windows PC systems, including performance mode features for high frame rates, quality features for 4K resolution gameplay.
Bug fixes and bonuses for the Creation Club are also included in the update, which is free for anyone who has already purchased the game for the respective format. However, there is no firm date for the update.