Wish I could use this, but Safari only started supporting this as of 15.4, which was released less than a year ago. I'll likely have to wait another 2-3 years until our site stops seeing these older Safari browsers.

EDIT: looks like Firefox released support around the same time, but my company's Firefox users seem to be all be ok more recent versions.

Surely there is a polyfill you can use?

https://github.com/GoogleChrome/dialog-polyfill