I have been searching on the internet using Selenium (Java) interacting with Google Chrome Extension but have not been able to find an answer.

First Question
Is there a way to launch the chrome extension since Selenium only interact with WebView but not on the chrome extensions button in the browser ?

I try this method 
"chrome-extension://id/index.html" but the extension did not launch as expected. I like find if there is another way to launch a chrome extension through selenium

Second Question
I am trying to click on the elements in a chrome extension with Selenium webdriver. How do I do it ? I tried the driver.CurrentWindowHandle , but it does not detect the chrome extension.

Thanks