Pressing Space not previewing item

The documentation says that in Project View “You can see a full-size preview of any of your items by pressing Space. Press Space again to clear the preview”. However pressing space on my computer does nothing. Is the feature broken or am I missing something here?

This is only supported on macOS at the moment (using macOS’ native preview window).

Ok. Thank you for making this wonderful software and taking time to answer the question,