What it means for your invitation
A livestream needs no invitation at all; it needs promotion, which is a different discipline and a different page. A webinar needs a page whose whole job is to convert a visitor into a named registrant before the room fills. So put the subject and the running order high up, the speaker plainly, the date with its time zone as a label, and the room size honestly. Then make the confirmation do the quiet work: an access link belonging to that person alone, a calendar file and a Google Calendar link, and automatic email reminders at set intervals before the start, which the host can switch off.
One thing our product does not do, stated plainly because the comparison invites the assumption: we do not broadcast. There is no stream key, no channel, no embedded player, no viewer counter and no live dashboard. If you want to push a signal out to everyone who happens by, that belongs to a streaming platform, not to us. What we do is the invited-room half: the registration page, the seat limit and waitlist, the private access link, the email reminders, and the list of names with statuses you keep afterwards. Plenty of hosts run both, streaming the public session and using a page for the closed one, which is a reasonable arrangement as long as nobody confuses the two.