uber assist not showing on my app

I read somewhere you can put the promo code assist in your uber app and it will tell the driver that you have a disability, and then I read somewhere else that it's a whole other uber option that will be available on your phone. Thinking it may have just been heresay, I entered assist on my phone and it accepted the code but I don't see a uber assist option. Is this a feature only available in select areas? Will it really tell the driver I have a disability?
Thanks.