(a) As used in this Section, “Internet website or web service” means any third party online curriculum that is made available to enrolled students or the public by a school district through the Internet.
     (b) To ensure that the content available on an Internet website or web service of a school district is readily accessible to persons with disabilities, the school district must require that the Internet website or web service comply with Level AA of the World Wide Web Consortium’s Web Content Accessibility Guidelines 2.1 or any revised version of those guidelines.