One more step — pin the extension so it's always one click away.
Click the extensions 1 button in the toolbar, then click the pin 2 icon next to Fact Checker:

Now click the pinned icon 3 on any page to start checking facts:

Once the extension has been installed, you will need to refresh the page for it to work properly.
Scientists report that coffee reduces heart disease risk by 40% in a new study.
Highlight text
Select any claim on a webpage
Click extension
Open the pinned Fact Checker
Press Check
Get your verdict with sources