Documents can be uploaded to the portal by using the Upload button and selecting files, or by drag and drop.

Upload: Upload a file into the documents section - if you click on one of the filters prior to uploading, the document will be attached to that filter. If you have not selected a filter, the document will be unassigned. 

Drag and drop: you can drag and drop a file onto the website and the document will be added in the same method as uploading - again if the filter is selected prior to dragging the file across, it will be added to that filter. When dragging a file to the portal, you will see this screen - drop the file when that screen appears. After adding the file, you will see the progress for the uploads in the bottom right hand corner of the portal page.