I have ordered scratch (expensive) and layer pellets from Amazon during covid. Be careful with raw rice as it can swell when exposed to fluids inside the body. Cooked or semi-cooked is better under most conditions. It's there. You can also order sunflower seeds online and mix them in, esp in winter. And sometimes I make or buy suet with plenty of fat and seeds of various kinds--maybe even in peanut butter. I think you can order those kinds of things. Good luck.Oh cool that you live in Canada its really pretty there. I think they sell some mealworms and corn mixed together on Petco. If you don't want to buy that than you can also mix some corn with radish and mealworms and other vegetables. I can make you a list of vegetables and other foods they can eat if you like.
My hens love left over cooked rice & pastaI've never heard of chickens eating rice but I guess that could work and here's the list.
whew that was a lot of words, lol