Install the OBS Spout2 plugin, restart obs, then turn on Spout in Veadotube and you can then add it to your scenes by adding a "Spout2 capture" Thats how I have been doing it for a while now :D
If you want to see how it looks you can take a peek at my vods on twitch (anubiswithcoffee) Also with this method you dont need to chroma key!