Publishing Engage 360

Hi, I can't find instructions for how to publish an Engage 360 interaction for use in a Storyline 360 file. The instructions included in this article don't specify the following:

1. Do I publish to web or something else?

2. Do I save the file as a .zip?

3. What file or folder do I select when importing into Storyline? If it's a .intr file, where do I find that?

Many thanks!