Chrome may add camera capture for file uploads on desktop. Websites can open your webcam instead of the system file picker.
While a webcam will suffice for most streaming, if you want to take a step up to higher camera quality, hooking up a DSLR ...
AVerMedia CamStream 4K is a niche capture card, but it excels at its one purpose: turning any DSLR camera into a pro-grade webcam.