You'll need to download and install the Developer Console mod, and then activate it in Bannerlord's launcher window. While Bannerlord doesn't provide a command console for entering codes, there's a dev console that can be activated by using mods.
Ctrl + H: On party screen, add 1 troop to currently selected troop type.Ctrl + X: On clan screen, add 1000 Influence.Ctrl + (1-6): On character screen, add 1 point to single attribute.Ctrl + A: On character screen, set all attributes to 10.Ctrl + Shift + F3: Knocks out your horse (if you're sitting on it).Ctrl + F2: Knocks out one of your own soldiers.Ctrl + Shift + H: Heals your horse to full health.Ctrl + Alt + F4: Knocks out entire enemy army.Ctrl + F4: In combat, knocks out an enemy.