Preparing students with disabilities for college

I have a child with extreme and debilitating testing anxiety. We handled it by pulling her out of public school into a progressive private school and applying to test optional colleges. I don’t think she’s taken a test in the past 3 years. We would like to get testing accommodations in college like a separate room where she can walk around if she needs it, but other than an anxiety diagnosis, we’ve got nothing. I’m not sure how to proceed.