In California, the courts said that ADA applies if the website has "nexus" (that is, connection) to a physical location. So, plaintiffs can sue restaurants (or other businesses) for not making their websites compatible with screen reading technologies if the websites have a connection to the physical location. Thurston v. Midvale Corp., 39 Cal.App.5th 634 (Cal. Ct. App. 2019), see also Robles v. Domino’s Pizza, LLC, 913 F.3d 898 (9th Cir. 2019). What kind of "nexus" should there be? This seems to be a case-by-case issue.
Other courts did not apply ADA to websites, taking a more literal interpretation of ADA (Third and Eleventh Circuit federal courts). And, of course, some other courts applied ADA to websites regardless of nexus to physical locations (First, Second, and Seventh Circuits).
Even though there is no unity between courts, businesses should keep ADA in their minds when expanding their virtual and remote access to customers. Not only websites but also call-in systems must allow access to visually or mobility-impaired, deaf, and otherwise disabled customers. And of course, do not forget about the physical location. It must be ADA-compliant!