Permissions
Permissions for a participant are defined by the preset. However they can updated in meeting by calling updatePermissions for remote participants
Find the target participants
Permissions can be updated for either a single participant or multiple participant at once. Find the ids of the participant whose permissions need to be updated
const participantIds = meeting.participants.joined
  .toArray()
  .filter((e) => {
    return e.name.startsWith('John');
  })
  .map((p) => p.id);
Update permissions
// Allow file upload permissions in public chat
const newPermissions = { chat: { public: { files: true } } };
meeting.participants.updatePermissions(participantIds, newPermissions);
Allowed values for update permissions objects. Every field is optional
interface UpdatedPermissions {
    polls?: {
      canCreate?: boolean;
      canVote?: boolean;
    };
    plugins?: {
      canClose?: boolean;
      canStart?: boolean;
    };
    chat?: {
      public?: {
        canSend?: boolean;
        text?: boolean;
        files?: boolean;
      };
      private?: {
        canSend?: boolean;
        text?: boolean;
        files?: boolean;
      };;
    };
}