Essential: at least 2-3 professional cameras, a video mixer and a professional audio mix separate for the room and the stream. In addition: a reliable streaming platform, stable wired internet with at least 20 Mbps upload and graphic overlays.
For interaction: a digital platform with chat, Q&A and polls and an online moderator. Also make sure online participants can appear live on screen. Expect 30 to 50 per cent extra budget compared to a purely physical event.