If a parent cannot see a list of available conferences to sign up on the parent portal, please check the following:
1) the reservation time is not in the future or the past;
2) if the Make Private option in the Attendees tab is checked, make sure you have invited the parent to the conference.
If a parent can access the conference but can see no teachers to book appointments with, you should check the following:
1) you have invited teachers/teams to the conference;
2) this parent is linked with the teacher(s).