Option 1
Click on the 3 lines next to the search space and click on Calendars
Select the calendar you want to be added to and click add
If the calendar you want to be added to is not on this list, click on search for calendars then type the name of the calendar on the search box provided. Select the calendar you want to be added to once you see it and click on add.
The calendars you are subscribed to will appear on the column on the right
Option 2
Search for the calendar you want to be added to in the search box on the top right hand side of the page.
Click on the calendar you want to be added to when you see it listed on the drop-down menu below the search box
The page containing the calendar will be opened
Click on the 3 dots next to the calendar name and click on subscribe
