Another favourite of mine is adding sprouts to my bird's meals! Sprouted seeds and grains are more nutrient-dense and are packed with proteins, vitamins, minerals and enzymes. They are also lower in fat and offer a lot of health benefits for your budgie. I will talk more about sprout seeds, but few things you can try sprouting are mung beans, millet, buckwheat (in null), lentils, quinoa and chia! I prefer making my own tiny mixing sprouting mix and sprout them in small batches. I also use a mason jar to sprout my seeds/grains! It's more cost-efficient! You can also find many online shops that have their own sprouting mix!
Ensure that regardless of which bird comes to your home, it's your responsibility to provide it with the best care and diet. Always ask your veterinarian about a specific diet for your bird about its specific needs.