What kind of expert can I talk to about whether I can get a disability extension for COBRA insurance?

My COBRA health insurance is going to expire next month and I’m trying to figure out if I can get it extended since I have a medical diagnosis of a disability. I think there are too many specifics here to get good advice from a Reddit post :P, so:

What kind of person should I seek out to get definitive answers about whether my COBRA carrier is required to extend my COBRA coverage?

I know COBRA is regulated via a law, so maybe a lawyer, but that seems like an odd place to go for health insurance advice. Trying to look up health insurance professionals mostly gets me brokers, though, who obviously don’t have an incentive to keep me on my current health insurance.

I know eventually I will need to talk to the company I get the COBRA insurance through but I don’t trust myself to be able to speak to them and get actual answers if they’re reluctant to extend my coverage. I want to make sure I know what I’m entitled to before I attempt to talk to them, if at all possible.

Thanks

(copied from r/Insurance where I posted this first, sorry if anyone sees it twice)