European Accessibility Act (EAA)

The EAA sets EU-wide accessibility requirements for certain products and services which are key for the inclusion of persons with disabilities in our digital world.

European Commission (commission.europa.eu)

The technical conformity definitions for this law are covered under EN 301 549:
https://www.etsi.org/deliver/etsi_en/301500_301599/301549/03.02.01_60/en_301549v030201p.pdf

In the US there are a couple applicable laws. There's the rehabilitation act of 1973, most notably section 504 which prohibits denial of service on the basis of disability for federal programs and activities that receive federal funding.

Challenge Validation

(www.dol.gov)

There's also section 508 of the Americans' with Disabilities app which mandates all government websites and applications used internally be made accessible:
https://www.section508.gov/

And there is the CVAA which requires consumer digital communications and video equipment or apps be made accessible, enforced under the FCC via a civil complaint process:

https://www.fcc.gov/consumers/guides/21st-century-communications-and-video-accessibility-act-cvaa

Then there is the Accessible Canada act
https://www.chrc-ccdp.gc.ca/individuals/accessibility/about-accessible-canada-act

Indian Rights of Persons with Disabilities act
https://cdnbbsr.s3waas.gov.in/s3e58aea67b01fa747687f038dfde066f6/uploads/2023/10/202310161053958942.pdf (they actually have three aplicable laws, this is just the most recent)

And so on.

The definitions of how to comply do varry and overlap somewhat, but many of them sight the Web Content Accessibility Guidelines as the gold standard
https://www.w3.org/WAI/standards-guidelines/wcag/

HTH! Surprised you didn't know any of this, some of these laws have been on the books for decades.