When the signature process is completed, the signed document will be available to download. Remember that you can always download a document in progress, although you need to keep in mind that it won't have all the legal guarantees.
From the three dots icon:
Search for the document in status "Completed" and click on the three dots icon. Click on "Download document" to start downloading it.
From the request's details:
Click on the document to enter the details window and click on "Details" on the right side of the screen.
Click on "Download document" to start the downloading process.