Open up your agendas by tapping on the second button on the sidebar (highlighted in blue)
To select the agenda in Tablet mode: Hold down and drag
To select the agenda with a keyboard/mouse: Right click
The option to share will now show on the top tool bar. Tap Share.
A notification will show in the bottom right corner.
If you are the administrator, you can now follow these steps: Sharing Agendas in Media Manager