How much do you pump, and how often?

I’ve tried everything to get my supply up but nothing has helped that much. I pump about 3 ounces every 3 hours.

(11 weeks postpartum. Started pumping at 2 weeks pp because baby lost over 10% body weight. Now he won’t latch and only wants bottles) I’ll pump until he’s a year old but I’d love to make more so he doesn’t need any formula top ups.