Formula

My baby is almost 10 months old and I give him formula as I was never able to get enough milk to breastfeed. Anyway, I know a lot of people that switch them over to regular milk or whatever mom chooses is best at a year old. Am I able to still give him formula after a year old? or do I have to switch him? I told my auntie we just stocked up on a few cases of formula and she gave me a puzzled look and asked why he doesn’t drink just regular cows milk yet..

I figure eventually yeah he will be off but I didn’t really want to right away.🙈 I’m a FTM just needing some advice! Thank you💙