Set browser resolution for CircleCI cimg/node:lts-browsers

I'm using cimg/node:lts-browsers in CircleCI to do some UI automation tests with TestCafe. However, the default browser resolution is pretty low, how do I change the resolution to something like 1900x1080 or whatever the max is for the image? I'm guessing you can set that with some env var like

      - image: cimg/node:lts-browsers
        environment:
          TERM: xterm
          SCREEN_WIDTH: 1900
          SCREEN_HEIGHT: 1080

but not sure what the actual env vars are. thanks!