Low milk intake - but very frequent

Hi mummies, I wanna seek for an advise about my baby low milk intake habit. He is currently 6m exclusive BF with bottle. I would like to know how I could change his habit from consuming 2.5 - 3 ounces per feeding for every 1 - 2 hours. As I couldn’t do anything only focus on his feeding. I tried increase and feeding him more and hopefully it help to make him get fuller but he will just turn his head away or close his mouth showing he’s full and sometimes throw up if I continue to feed him. At his age he should be consuming 6-8 ounces per feeding. Besides, he’s awake quite frequent at night craving for milk! Please help..