You have to pretend that Zoom doesn't work and then it eventually gives you the "join from browser" link.

When you click on a Zoom meeting, it will prompt you to launch xdg-open -- cancel it. Then hit launch again -- cancel the xdg-open again -- and then the "Join from browser" link should pop up after a few times.

Sometimes it tries to capture you, I had to click on trucks and trains for 15 minutes before it let me in, and then had to apologize for being 15 minutes late to the meeting.