In webinar rooms, the attendee/student enters as a mere listener (without a webcam or microphone) but has the option to request that the instructor/presenter give them a voice (enable their microphone). This is done through the hand icon in the student/attendee's virtual room.
When this icon is pressed, the speaker/instructor in their virtual room receives a notification informing them that there is an attendee requesting voice (enabling the microphone is optional):
The assistant/student requesting the voice appears in orange in the "attendants" section:
When the speaker/instructor wants to enable the microphone, they just need to press the microphone icon (many students press this button without having a microphone, so you should make sure they have one):
