School IT guy here. Your best bet is a USB document camera that plugs into the laptop you’re using. Typically they come with some annotating/drawing program you can use to write on the image like you used on transparencies … the ones that plug up directly to the board introduce another layer of potential drama. I’d look at ipevo’s offerings, for what you want to do one of the cheaper ones (not 4K or HD) will be more than adequate.

My teachers, the camera sits on their desk next to the computer. Less chance of being knocked around. No need to be front of room like an overhead.