Possibly the Greatest Alchemist of All Time

Possibly the Greatest Alchemist of All Time Summary:

Not even a hero, Takumi Iruma gets accidentally mixed in with a group of heroes chosen to be summoned to another world. As compensation for the mix-up, a goddess offers him the right to choose any skill he wishes for! Hoping for a peaceful and quiet life that has nothing to do with fighting or going into battle, he chooses a seemingly boring creation skill. However, it turns out "alchemy" is the most powerful skill that allows him to create everything from a holy sword to flying ships! This cheat skill he unexpectedly acquired turns him into a wealthy merchant and makes him undefeatable in battles! A heartwarming adventure story about (possibly) the most powerful alchemist in another world!

(Source: AlphaPolis)