Brand new looking to use my smartphone for video and audio--will that work okay?

I've been thinking of taking the plunge and running a Roll20 5e D&D game, but I haven't done it before and the tech side of it is a little intimidating if I'm honest. Mostly I don't have a webcam on my hand-me-down computer and am curious about using my smartphone to provide my audio and video feed. Is that workable? I have the Roll20 app for my phone and an account on my computer. The thing is, I don't know how to hook the two together and I'm not sure how much of that I can do without having other folks in a session cooling their heels while I figure things out. It's made me a little leery of getting started with my game until I can figure things out. Anyhow, any help folks can provide, I'd greatly appreciate! Thanks.

I don't think the built in audio/video will work with a smart phone. I would suggest using a third party audio/video solution. I use Zoom and Discord, both of which have web, native, and phone apps that work well.