Sharing in case anyone isn't familiar with this built-in capability:
google-chrome --headless --screenshot=my_screenshot.png https://www.example.com
google-chrome --headless --screenshot=my_screenshot.png https://www.example.com
And I guess this is exactly what this service does under the hood.
So it's installed now but still un-personalized like it was installed 5 minutes ago. I don't use it except with Antigravity.
Works fine.