You can embed a Sketchfab model on any HTML website. To find the embed code for your model, click the Embed button on a model's page, under the viewer.
To embed the model viewer in another site, click within the code to copy and paste it, and then add it into your site's HTML. This will work almost anywhere on the web; if the HTML iframe tag is supported, you can embed a Sketchfab model.
For sharing to social platforms, see Share Online.
Click within the Format or Size windows to adjust the embed viewer code.
Additional options can be unlocked by clicking the Upgrade to Unlock link and upgrading your Sketchfab plan. For details on Sketchfab plans at a glance, and how the embedded viewer looks for each, you can explore them here: PRO, Premium, or Business.
For example, if you want to hide the user interface elements and make your model start and spin automatically, your iframe's src URL could look like this: