Google "HDMI to USB Adapter" for some ideas.
The HDMI port on most laptops is HDMI Out from the laptop to a display such as a projector or television. One of the HDMI to USB Adapters will take HDMI and adapt it so that when you plug the USB end into a laptop port you will see the video and be able to do something with it. (Put it into a Zoom meeting or webinar, pull it up in OBS, or something similar.)