It's just a link to open sketchfab but it works awesome. It opens up a new screen and loads the model. It was glitchy at first but now once the new screen opens after you click the link, look at the top of right and click on the open in the chrome button. Opens a new tab and works every time.
Get your share link from your sketchfab, right click on your Google Earth map and add a place mark. In the add url box paste your code there and click OK. Let me know if that works for you.