Spacer web part - Horizontal space?

Has anyone used this functionality of the Spacer web part:

Drag the gray bar up or down for vertical space; "drag the corner boxes in or out for horizontal space". Or, use the up and down arrow keys to resize.

I use it for vertical space, however I have never been able to use this for horizontal space - as the Microsoft guide proposes: https://support.microsoft.com/en-us/office/add-vertical-space-to-a-page-with-the-spacer-web-part-7e6ae288-1634-44e2-bc4c-7fb4042ee905