If I were you would go to head-fi.org and take a look around if you haven’t done that already. Headphones dedicated site that often times ask for reviewers, mostly voluntary, but still get you a foot in the door. Hope that helps.
How do I get a job as a headphone reviewer?
I'm partially disabled and have a hard time with most jobs, but I can work a little part-time especially if it's low stress.
I've had high-end equipment, especially headphones, for 20 years. I'm also an amateur musician and have an analytical and music-oriented "ear." It occurred to me... maybe I could be a reviewer. Maybe it would be a nice part time side gig. But how do reviewers get their jobs?
I live in a small apartment and don't have a place for speakers with any kind of good room set-up... so it would have to be headphones I review, or headphone amps, also DACs, computer audio, and that kind of thing.