You can use the built in service that zap.stream offers. OBS or Owncast.
Discussion
The built in service charges x sats per minute. Trying to avoid that OBS does not work for me so I will look into owncast.
If you don't want to pay owncast is a good option, if on phone you can spin up node-media-server and use BroadcastMe and fire the link up a kind1 or a kind 30311(streaming event) note. The lag will depend on the connection in any case.
Good to know if I ever need to do any mobile streaming. I will see if I can get owncast to work with it i'm trying to make a 24/7 jukebox.