The basic way of running your test cases within the interface in order to see wether they pass ("checked icon") or fail ("red cross icon") is using the "Play" button.
By turning on watch mode, you no longer have to run your tests one by one! The interface will run all test cases as they are added/modified. In addition to running the tests, toggling watch mode will trigger the "Bolt" button dynamically for all the generated test cases in the Suggestions section.
The toggle button can be found at the top of the interface.