To check what version of the web softphone you are using, click the "hamburger" menu on the top left of the screen (if you don't see one, you may need to maximize or fullscreen the window that your phone is in), then scroll down and click on the "Settings" gear. At the bottom of the menu, it will say "Version" with a…
1. tap the 3 vertical dots in the top-right corner of the screen and then tap Settings iOS 2. Tap About 3. Note the version number at the bottom of the screen