You can already point it to an image url with an image in the right resolution on the internet, and it will render that.
But for pointing it to an HTML page, you need a headless browser and that comes with a bunch of practical issues.
I don’t see any obvious answer for this, but how often does it query / refresh the image URL?
I’m thinking of writing some script to just push an updated image to something like https://example.com/dashboard.png every 15 minutes or so.
You can already point it to an image url with an image in the right resolution on the internet, and it will render that.
But for pointing it to an HTML page, you need a headless browser and that comes with a bunch of practical issues.