For the mean time, we can suggest using virtual cameras such as the Snap Camera to show a background. This does not work for Safari but works for other browsers.
Install the virtual camera software
Search for your preferred search term such as "blur background" and pick what your like
Start a Virtual Consult inside SeriousMD and click SETUP CAMERA & MIC
4. Pick the Virtual Camera that you are using to output the virtual background that you want.
5. Click Choose Device and start your Online Consultation