I don't believe you can assign an individual passcode for each participant but you require registration and a waiting room to allow them in one by one.
Thanks, the expected number of participants is ~20÷50 and I'd rather avoid to manually accept them one by one from waiting room. Participants have paid to attend and I don't want them to share their credentials and allow other persons in the meeting (of course I cannot avoid they watch together with other people from the same physical room). Does this mean I have to upgrade my account and purchase a license for Webinar?