Staff with Essentials accessing calendar

I and the other designated admins have premium. Our techs, who are almost always on the road, only have Essentials. Can someone with just Essentials view the Bookings calendar? I could log in with one of the techs on the Bookings mobile app and they could view the calendar just fine, since they're all designated as a 'viewer'. However, today, it says Bookings disabled when I check it again as that user with Essentials. It's important that the techs have the the ability to see the calendar to see not only their own schedule, which I know syncs up with their personal, but also their fellow techs. The only question that I could find that was a similar case, no one ever bothered to answer or even respond to their question.