Owncast if you've got a decent enough internet connection.
Consider- a 'decent' 1080p h.265+opus stream will be around 8mbps, if you've got 10 devices watching, that's 80mbps, you'd really want 100mbps+ upstream bandwidth to do that.
If you're lucky enough to have 1GBPS/1GBPS, then you're probably fine for a hundred or so devices, if you're stuck on an asynchronous connection, do consider how much upstream bandwidth you (they) have.