Mod, add-ons

Can someone else program my Unreal Engine 5 game to add mods or add-ons to it?

Hey there @gigachadjeremy! Welcome to the community! The question is dependent on a ton of factors. Are users able to modify the game with known utilities for Unreal games? Certainly. How effective is it for each game? This can vary.

Are you trying to make modding easier for your users?