Does anyone know How to find a medical advocate?

I was wondering if anyone has a clue how to find an advocate to help navigate and fight for services with insurance companies? I don’t even no where to start.We have to get help for my 11 year old daughter and it is not going to happen here in Denver. We saw a second neurosurgeon that our insurance forced on us. It was awful. We are trying to sort out a CSF leak and all she wanted to do was call Dr. Frim aggressive and try and prove him wrong on the Chiari. We really need to get Dr. Frim covered.

Thank you.