Webpage empty for visualizing URDF

[kavikode]

Following the instructions in Ubuntu 22.04. I did

pip install -U 'vuer[all]==0.0.32-rc7'

gedit vuer_example.py with the contents:

from vuer import Vuer, VuerSession
from vuer.schemas import DefaultScene, Urdf

app = Vuer()

@app.spawn(start=True)
async def main(session: VuerSession):
    app.set @ DefaultScene(
        Urdf("assets/urdf/robotiq.urdf"),
    )
    while True:
        await session.sleep(0.1)

I run the script with python3 vuer_example.py

sudo apt-get install git-lfs git lfs install git lfs clone https://github.com/vuer-ai/assets cd assets/robots make # Downloads example robot URDFs

I open the browser to the http://localhost:8012

There is no robot visible anywhere and it is empty screen. Please help.