Proclaim supports live video feed on your slides during your presentation. You will need a video switcher that can utilize either:
In the video above, we're using an ATEM Production Studio 4K switcher to accomplish this. Anywhere you see the checkerboard pattern behind your slide is transparent and will be filled in with the output transparency color that you select in the Settings menu:
By default, Proclaim will fill any transparent portions of the slide black. For live video feeds, select one of the two key colors from the list. On your switcher, set the video feed to the color you've keyed in.