Yes. I believe the school district has to do the evaluation. The consent is from the parent, not the child. That the child refuses itself can be an indicator of educational barriers.
There are other ways to evaluate even if the child is non-cooperative: parents' interview, current performance, current observation, physicians, a review of the child's past work, a review of child's past behavior in comparison to current, teacher's interviews, private therapists or psychiatrists, a neuropsychologist, Children's Hospital Child Development Clinic Evaluation, etc.
It is actually not uncommon that a child of that age resist cooperation, for reasons of opposition, fear of stigma, etc.
My child never refused, but I dealt with non-cooperative school districts. There are agencies, the one I worked with was called Disability Rights, that can provide assistance and possibly representation. In our case there was discrimination and bullying involved.