The extension is launched by a single left-click on the Examus icon in the upper right corner of the browser:

 

The Examus icon can also be displayed in the dropdown menu that appears when you click on the browser extensions menu in the upper right corner:

 

If you do not see the Examus icon, or it is inactive, it may mean that the extension is installed, but inactive (turned off). Open the link you have downloaded the application from and click Turn on:

 

You can also use the chrome://extensions/ link in Google Chrome (or browser://tune/ in Yandex Browser or edge://extensions/ in Microsoft Edge). On this page you will see a list of the extensions installed. Make sure that the extension is in the list of installed extensions and that it is active (enabled):

 

Learn more about managing extensions: 

https://support.google.com/chrome_webstore/answer/2664769?hl=en