Invite only set up involves providing an email address for each of the voters.
Invite only does not send invitations, it simply means that people must use an email address to login to the meeting. This address does not get verified, so if you wish to create email addresses that are not actually functional but are just for use as a log in, that is fine.
If making up login emails, we recommend keeping it really simple. For example if my meeting was called June Away Day, I might use something like clare@jad.com.