Phone and video conferences work with internal and external participants.
A password for a conference can be set, as long lobby (for webinar) is not selected. As soon lobby gets selected, password box stays unticked.
Lobby only works if a start time in the future is scheduled.
If no start time is scheduled or one in the past, the participants see the lobby forever and can’t join the call.
It seems a start time is necessary although the field says it is optional.
Although - I don’t find this approach to be straight forward for the following reason:
I have a regular webinar setting without a start time but the lobby setting ticked. Every time I untick it I have to remember to tick it again for the next session.