Overlaying a widget or browser source over stream

I’ve been considering purchasing an FBE200 for a while now, and will do so if I find some way to accomplish the following. I want to use the encoder as a mobile streaming rig to stream my gopro to youtube. As I won’t have access to a laptop (and therefore no OBS or streaming software), I need to figure out how to overlay my streamlabs widget over my stream so I can use text to speech and have audience interaction. Is there a way to do this within the encoder’s settings or via external hardware?