Need a very simple collaborative draw/ whiteboard software with audio-video conferencing feature.
Draw.chat virtual classroom is the best. However it is web based.
zoom has screenshare feature where you can share whiteboard instead of screen. It allows you (and others) to draw on it, although the functionality is not comparable to dedicated drawing programs. You can also draw on shared screen which I find extremely helpful. Besides of that, it is a major videoconferencing tool.
You could use Whereby. It has an integration with Miro whiteboards. You don't need to register in order to use either Whereby or Miro.
It also has Google Drive and YouTube integrations, but it's a pretty powerful service, and it's free.