I'm late to this, but I think it works better (quality and stability) if you install it, but there is a web-based version like everyone else has already said.
Anyhow, I came here to say that I found a load of empty TV sets to be used as backgrounds by the BBC including
Dr Who and
Blakes Seven that you can download here:
The joy of sets
When I tried to use virtual backgrounds (without hanging up a green curtain) I got very poor results. Does anyone have any advice for using virtual backgrounds?
Also, we should say that other videotelephony software programs are available! Actually, the most annoying thing is that everyone wants to use something else, and I don't want to fill up my laptop with Microsoft Teams and Skype and whatever their personal favourite is today.