You may request the software 8.1 from Pega Digital Delivery - https://community1.pega.com/digital-delivery and once you download the software, please look for Accessibility PegaWAI zip file by navigating to Media software -> ResourceKit -> AccessibilityFramework -> pxWAI ruleset
Thanks for reaching out, I'll confirm that we have the license for the ruleset and then look under that directory to confirm. Currently when we try to use the Import Wizard using the "From Server" option, no files are available. But we'll check again on the server.
Please try downloading the media on your local system first and confirm if you are able to import the zip file from local system, once its imported you may add the ruleset to your production ruleset of your application.