In the email editor, if you would like to add any panel, simply click on it to pick it up, then drag and drop it into your template.
Add several panels to create a section, e.g: add a heading, followed by a property panel, followed by a spacer.
Make sure to click Save after making any changes.
If you cannot add a panel in a specific spot or email, the email may be restricted. Contact your admin or ActivePipe support to discuss why.