Setting Rectangle Material to an image dataURL

I have an image's dataURL (image/png base64) and I want to be able to set a RectangleGraphics material to the dataURL but can't seem to get it working. Does someone have an example on how to accomplish this?

Hi Kevin,

I don’t have any examples offhand. The MDN Web Docs describe some potential issues here.

Could you provide a short Sandcastle example to troubleshoot?