This trial tests if smell retraining therapy and budesonide-saline nasal rinses can help children and young adults regain their sense of smell after losing it due to COVID-19. Smell retraining involves smelling different scents regularly, while budesonide-saline rinses aim to reduce nasal inflammation. The study aims to see if combining these treatments is more effective than smell retraining alone. Budesonide has been widely studied and used in various nasal treatments, including for allergic rhinitis and chronic rhinosinusitis.