A perm (permanent wave) is designed to add curls or waves to straight hair. It uses chemicals to break and reshape the bonds in your hair, resulting in a different texture.
To make your hair straight, you would need a chemical straightening treatment like a Brazilian Blowout or Japanese hair straightening. These treatments work by permanently altering the hair's structure, making it smooth and straight.
Keep in mind that both perms and chemical straightening treatments can be damaging to your hair if not done properly.