How do you evolve a traded pichu and i don't have a smoth bell?

To evolve a traded Pichu into Pikachu without a Soothe Bell, you simply need to increase its friendship level. You can do this by walking with Pichu in your party, using items like vitamins or berries that boost friendship, or leveling it up. Once its friendship is high enough, you can evolve it into Pikachu by leveling it up.