Zoom Webinar - mute virtual attendees?

Hi,
I'm co-hosting a webinar and supposed to assist to mute attendees and disable their right to unmute, I'm aware that such options exist via this screenshot below, can you please advice where / which menu opens these options:

https://monosnap.com/file/BBibs37X0grlKgaSv49LqMrr0ERhSG

Thanks!