When attempting to download the Web Dialer extension for Safari, you receive a message that reads, "'8x8 Web Dialer' is no longer supported. You can find newer extensions reviewed by Apple in the App Store or Safari Extensions Gallery."
- 8x8 Web Dialer
Safari blocks support for legacy extensions that come from outside the Safari Extensions Gallery.
Use Google Chrome, and install the 8x8 Web Dialer extension from the Chrome Web Store.