Using this method, you can import supported media files wherever they are hosted on the web--as long as it has URL and doesn't require a login, Scalar should be able to use it. Note that importing media from sites you have no relationship with risks future "link rot", as the site's owner may move or remove the file unexpectedly, thus causing it to disappear from your Scalar book without warning.
To import online media, click the import icon on your Scalar header bar and select "Files and URLs" and then "Link to media files". The corresponding import screen will appear.
Enter a title and description for the media. The title is required, the description optional but recommended, as it will be used as a caption for the media in specific places in Scalar.
Enter the URL of the location where the media is hosted (the media will not be moved into Scalar, only loaded from that location).
If you wish to create any relationships for the media you are importing, or to edit its styling or additional metadata, do so using the links below (this is not required and can be modified later by clicking the "Edit" button while on the page for the media file).
Click Save, and you'll be taken to the page for the newly added media file in your book.