Formula question

svel💖 • 2👩👧 1 ectopic 2 👼👼 1🌈 born 11/4/19

I read online u can feed baby on demand and it’s ok if they eat less or eat more at each feeding?

My baby is almost 1 month and eats 3oz every y 3-4 hours but sometimes she acts like she’s still hungry by looking for nipple crying ect I give her 1 oz more n she’s fine. She never spits up but just want to make sure I’m doing this correctly I havint had a baby in years lol 😂