How to produce more milk ...

Brittany • Mama to 2 girls! 💗 🤰🏼 with number 3!
I'm 1 week post partum. I have been pumping every 3 hours since she's been born. I'm still only getting 1 ounce everytime I pump. I'm not nursing her cause she is 4lbs and needs to be supplemented with formula.. And she has no interest in latching on. Any helpful hints on producing more? In getting to the point where I feel like giving up.