As with most accessibility problems... Checking my User Agent won't tell you how I'm interacting with the site. How do you detect I'm using NVDA? It'll still l

As with most accessibility problems... Checking my User Agent won't tell you how I'm interacting with the site. How do you detect I'm using NVDA? It'll still look like Firefox. Or Chrome if I'm bypassing a broken UA detection. Nowhere will you see NVDA, even though it is the problem.