How can I produce more milk

seahorsedad|👶🏽👶🏻👶🏽🌈|mcchicken

My baby is 4 weeks. From day one I was making 4oz each pump session (2oz each side) then went from 2oz (1oz each side) then when she was 2 weeks old I barley pumped an oz all together now I’m only making barley half an oz each time. Idk what to do. (Pic of my girls)