No SSO in Zoom unless Firefox is installed

I am unable to do SSO in zoom-us in any other browser but firefox or firefox-wayland (zoom-us installed via home-manager in sway). (Joining a meeting works fine.) How do I get zoom-us to use my default browser (ungoobled-chromium) for SSO?

I captured stdin and stderr on startup without firefox installed found a line which indicates that zoom-us cannot find a browser:

Unable to detect a web browser to launch ''

Created a pull request to fix this issue: zoom-us: add xdg_utils to PATH by xfix · Pull Request #100560 · NixOS/nixpkgs · GitHub. You may try to install xdg_utils to workaround this issue until it gets merged in.