You did have to pay, but it was massively supplemented by the govt with their food stamp program so you didn’t pay much. Which makes sense, a lot of the people who needed this food were women with kids to feed and husbands overseas fighting. Fun bit of trivia, a shitload of people sent in what stamps they could when queen Elizabeth was married so she could afford her dress. She didn’t actually use them though (I forget what happened to them).