When in an interactive class, you will appear as 'Guest' by default. To change this and replace with your actual name, hover over your video tile, 3 white dots will appear in the top right.
Clicking on this will present you with the option to Edit display name.
Click on this and a popup will appear as shown below. Replace 'Guest' with your name and click Save
You will now appear with your name to all participants in the Interactive Class.