Greetings, Maggie typing for Jayd
Continue with your formula and work your way up to 60ml or until he rejects it. Give him a half teaspoon unsalted peanut butter each morning for breakfast...let him eat it off the spoon. Up until now, he has relied on you to feed him. So, you can use your fingers to feed him. Also, he is more likely to eat off the floor instead of a bowl. Stay away from the fruit, no more than one piece (the size of a grape) grape or apple is good.
Cheerios on the floor is excellent. Put a small pile of seeds (no sunflower seeds) 24/7, for example, Volkman's Hookbill is an excellent choice. Through the cage bars, stick a partial leaf of kale, mustard greens, etc. and change often. Food must be present 24/7...it's called abundant feeding. Get your baby foods, example: Squash, sweet potatoes (no corn) (Baby's 1st year), birdie bread....a simple recipe is Jiffy Cornbread mix, 2 jars of baby food, egg, and vegetables (mixed or your choice), seeds...the best part of this is you can get creative and add what you want to it...bake and serve in small chunks for the baby to pick at.
Make sure the baby has plenty of water and watch what your baby eats. NO PEANUTS unless they are roasted, no salt, and MUST BE HUMAN GRADE...Check your parrot no eats food list before introducing anything new. When he is established eating, you can add pellets (which I personally do not recommend).
Thank you, Jayd