Her friends pay at the canteen with UPI. Is that a thing at 11?

My daughter is 11, in Class 6. A few of her friends apparently pay at the school canteen and the stationery shop with their own UPI, linked to a parent's account in some way. She wants the same, and she has made a reasonable case: she buys small things, I'm often at the hospital, and right now she has to borrow cash or wait for me. I'm not against her handling money. I'm less sure about a payment app on her phone at 11, and I don't understand how these junior accounts or spending limits work. If your child has one, how is it set up, and has it been more useful than worrying?