...
These videos have html examples:
'Estelle Weyl – “Fast. Simple. Accessible.“ | .concat() 2018,'
...
Kevin Powell’s playlist on Underutilized HTML elements
Kevin Powell’s playlist on https://www.youtube.com/playlist?list=PL4-IK0AVhVjMobWfe4VmvbAwLmpG1RQMT
'Introduction to WAI-ARIA (Accessible Rich Internet Applications),'
...
Advanced
https://developer.mozilla.org/en-US/docs/Learn/Accessibility/WAI-ARIA_basics
https://blog.logrocket.com/aria-live-regions-for-javascript-frameworks/
...