In PvE, 32 bag slots are a must-have for any serious player. The best way to get them is by crafting them, but there are also ways to get them through the game.
First, you can find them as rewards for completing certain quests or defeating certain bosses. Second, they can be acquired by trading with other players.
Finally, they can also be bought from the in-game shop.
Crafting is the most reliable way to get 32 bag slots, but it is not the only option. Trading is also an option, but it is not always reliable.
Finally, the in-game shop also sells 32 bag slots.