Does it have to be a video feed? Since you are teaching programming, there are m...

Does it have to be a video feed? Since you are teaching programming, there are multiple options to share editor sessions where the text is viewable on both ends. Then all you need is a voice channel.

VSCode has a live sharing extension (https://code.visualstudio.com/learn/collaboration/live-share), and there are some editors with this functionality built-in such as SubEthaEdit for Mac. If memory serves there’s even a Vim plug-in.

Looks like there’s a few online services dedicated to doing this in a browser: https://codeshare.io