Once you have a draft, sketch, or some other sort of “first pass” of the Deliverable file you want the client to check out, you can upload the file for their review.
Go to the Deliverables screen and click on the Deliverable for which you want to upload a file.
Select the “Review” tab.
Click the “Upload File” button to open the “Upload New Asset” pop-up.
Choose a Deliverable file from your computer. (Here's a guide to what types of files to upload.)
Click the “Add File” button to upload the file and close the pop-up.
The deliverable file will be displayed on the screen. Add a comment if you wish.