I get an error 1020.
Error 1020 is usually linked to a restrictive firewall. If you are in your company, ask your IT if they can help you.
I get an error 1004.
Error 1004 is usually linked to a browser error. To fix the error you can do the following:
I get an error NotReadableError: Could not start video source.
This error occurs when the browser cannot find a webcam. This is usually due to the client device.
Whether the fault is in the device can be tested on a page like this https://webrtc.github.io/samples/src/content/getusermedia/gum/
Possible causes for the error are: