In Figma, select the layer you want to add your media to
In the plugin, select "Media element"
Paste the URL of your media or upload your file, then press "Next"
In the next screen you can choose from many options, including autoplay, loop and mute. After you're done, click "Save"
This is what the result should look like:
⚠️ Your media cannot be previewed in the Figma prototype preview, only in Anima's preview, sync or after downloading the code to your computer - and in the generated code.