I am hoping to teach a watercolor class so would not use a computer screen. I would project the phone down onto the painting surface (art table) and be standing slightly behind and under it. Can I simply record using my iphone 11? If so, what setting do I use? 4K at 30/60? Do I need an external mic? And. maybe a dumb question. but how do I get the video to Udemy? Thanks in advance for any advice.