Girls, please tell me what mixture to give a child who refuses to eat …

Girls, please tell me what mixture to give a child who refuses to eat for some reason. I've been breastfeeding since birth. The first time it didn't work either. Children don't want to breastfeed. At first there was a lot of milk and I didn't even find it stressful. Then in spurts...a week ago, for example, I could even freeze milk besides feeding...and now I sit for an hour, struggling and can't get enough milk. Sometimes I really want to cry in such moments. Tried giving different types of mixtures as top-up feedings several times. But my daughter sucks on it, in the first second she understands that it's milk, spits out everything she managed