Step 1: Open the Environment pane. If the pane is not available, select "Windows," from the top menu toolbar. From the first drop down menu select “Panes (Tab)” and then select “Environment.”
Step 2: In the drop-down next to “Type:”, select “Backdrop.”
Step 3: Click on the arrow under Background and choose Browse.
Step 4: Browse and select the preferred background image and select “Open” The background image will appear in the viewport in Daz Studio. The image below provides how the final result should appear.