OB won’t do another ultrasound

Sandra • Wife 👰🏾👨‍👩‍👦 Mother to Ava love 3/29/18 👶🏾 Baby #2 🤰🏾😍🎀 6/30/20 🍼 👶🏾 RN BSN 💉💊👩🏾‍⚕️

So I’m 30 weeks no pain or symptoms but I want a recent ultrasound to see how baby is growing (weight, position n other stuff). She refuse and state baby is fine based on fundal check. What can I do to get an ultrasound that my insurance will pay for