Get to Chrome's Settings
Click on Chrome's menu and click "Settings".
Go to "Extensions"
On the left side navigator, click "Extensions".
What version am I on?
Look for the Dialer. Next to the title, there's a number. That's your current version.
To request for "Update extensions now" you'll have to check the checkbox for "Developer Mode". It's at the top of the "Extensions" page/list. After you do, the button will appear. Click on "Update extensions now". Give it a few seconds and you're all done!