​​​​​​​​​​​​In the toolbar on the right, on the "Attendees and Privileges" button, you can select the guest you want to give authorizations to in your Educast. You can choose among allowing users to have full access to the annotation tools, send files via the Chatroom, and other functionalities. The authorizations can be suspended at any time during the Educast, and they do not have to be for all: the instructor chooses to whom he/she will give which authorization.