Hello!
It's simple, you just need to download it!
Fallout 4 is set in a
post-apocalyptic Boston in the year 2287, 210 years after a devastating nuclear war. The player character emerges from an underground nuclear fallout shelter known as Vault 111, and subsequently explores the world, completes various quests and acquires experience points to level up their character. It is the first game in the series to feature full voice acting for the protagonist.