If you are not seeing specific inputs appearing as an option with a Decklink Duo, Decklin Quad, or similar multi-input Blackmagic device, the Blackmagic software maybe looking for the incorrect video format. 

Navigate to the Blackmagic Desktop Video software. You should see the device you are actively using appear, select the small file icon below the name and image of the device. 

Then select the Connectors tab from the options at the top.

Finally, change the Connector Mapping, to the proper video format, whether this be SDI or HDMI. 

Once you have made that change, restart Production Truck and you should see that change take place and those inputs, that were previously not there, be available within Production Truck.