What should I feed my backyard chickens every day?

[Skywalker]

I recently started keeping a few hens and want to make sure I am not giving them the wrong food. There is so much conflicting advice online about grains, kitchen scraps, treats, and complete feed that I am not sure what should actually make up the main part of their diet. I would rather get the basics right from the beginning than correct nutritional problems later.
What would you recommend I feed my chickens on a daily basis, and how much room should I leave for treats or scraps?

[Cloudy]

For the main diet, I would rely on a complete poultry ration that is formulated for the birds’ age and stage of production rather than trying to mix everything myself.
Chickens should receive a balanced prepared feed containing the necessary vitamins, minerals, and protein, with laying hens also needing adequate calcium and grit.
A helpful American overview on how to feed chicken also notes that fruits, vegetables, grains, and insects can be part of what chickens eat.
I would treat kitchen scraps and scratch grains as extras instead of letting them replace the nutritionally balanced feed.