you need a tripod with an over reach ability. It might be better to do it with two stands on either side of you however. You will also need a light ring.

I'm going to suggest something like this or this. as they give you the phone mount and light ring you need to prevent shadows. There are plenty of options out there however so provided you have a light ring and something to hold your phone/camera over your work without getting in the way or in the shot you should be all set. Also, a note about this sort of thing. Do test videos. Just something 2-3 minutes long but something where you go through the motions of what you are filming. This will help you see what you need to change / adjust giving you the best possible video.