Are you looking for a confirmed contract agreement? If you are able to pull up the boater's reservation: navigate to the documents section below the itinerary and click "view agreement" (screenshot below).
If you need to find the boater's reservation through your Contracts page use the following steps:
Navigate to your Contracts page in Dockwa.
Chose the Contract Group for that boater.
Once you see your boater's name look to the right-hand side of the line and click "reservation"
Now you will be on this boater's Reservation. Just below the itinerary click "view agreement"
You can choose File, Save As on your computer, or right-click (control+click) to bring up the drop-down menu and click "Save As" to download the agreement.