The Assets Window is where you can manage your Compositions and and external assets.
To import an asset either:
File > Import Asset...
Double click in the Assets Window.
Drag external assets from your OS into the window.
Supported file types:
.exr (single channel only for now)
.apng (animated pngs will often have a
.png file extension. Change this to
.apng for Cavalry to recognise it as an image sequence)
Google Sheets - see Google Sheets Asset.
The following codecs are supported for video formats:
h263, h264, h265 (hvec)
ProRes (422, 422 HQ, 422 LT, 422 Proxy, 4444, 4444 XQ)