After you have uploaded your documents under Files section.
Please click Edit.
After you clicked Edit, the Processing window will display.
Once the processing is complete, you will see the pages you have uploaded to fax and there are navigation control available for you.
Previous page / Next page navigation arrows
Page count indicating page you are on / total number of pages
Show thumbnails view of pages you are sending
Zoom in / Zoom out
Rotate left / rotate right
Remove pages from being faxed
Cancel any changes you have made and return to Compose fax screen
Save any changes you have made and return to Compose fax screen