Users can import shape files into the web tool, if they are compressed in a folder.
To import, click 'Add Layer'

Next, under 'Select a Layer' change New Layer to Upload  

Click 'Choose File' to select the folder containing the shape files. A window will open - select the folder and click Open.

Add a Name to the Layer. Click Create to finish. 

The Layer will then be added. It may take a few seconds for all of the data to be uploaded. Attributes will be imported as well. 

*Note: Data will be Internal. The attributes can be edited.