This is a neat and effective HDMI capture device I use alongside a BMD Ultrastudio Mini Recorder:
https://www.amazon.co.uk/gp/product/B07 ... UTF8&psc=1- ATEM PGM SDI into Mini Recorder into Thunderbolt 3
- ATEM PVW SDI into Bidirectional SDI/HDMI Converter into Diwuer HDMI into USB2
This provides two independently switchable inputs into Wirecast streaming software; adding screenshare from Zoom adds a third input, allowing for instance a three-vignette shot.
The Diwuer capture card looks like a webcam and also works reliably into Zoom etc.