Baby only eating 2 oz at a time

I posted on here before about this But I’m hoping to get more insight/others who deal with the same bc I am getting so frustrated with it. My 4 month old is basically just taking 2 oz and Sometimes 3 oz but I would say 85% of bottles she only takes 2 oz after 3 hours. I am at a lose what to do at this point and I feel like we are just going to be at 2 oz bottles forever. I’m not sure what to do or if anyone has dealt with similar. Thanks !