nostr:npub1437d992cqszvsnzpuy7jnec2w90dk4tfj57echyahg6ffu9y9t2s9kranm nostr:npub1vm2yasykvnuu3uhu6w45wnwd6p3lyv2q3kn6k3j98jptg0dxl76q8xuh2l There's no such thing as a live stream, or even media attachments, in the nostr protocol itself. When you attach an image or a video to a note, it's handled out of band. Your note will just link to a centralized server for that.
So any form of live stream would be the same. Just use whatever server/service/app to create the stream and link to it from your note.