64483, 64484 add-on charges

I work in a general clinic/pain management office, we have an anesthesiologist/pain specialist come in and do facet blocks/ TPI, the charges for the initial first level block, but there are no charges entered into our fee schedule for the add-on 64484, couldn't find a charge for it, pt has private insurance, not Medicaid/medicare. Should I call the insurance OR does anyone here know what the charge is for this procedure.

Still new to coding, any help is appreciated, thank you!

64483, 64484 add-on charges