You can add the attendance tool to your course menu with the following steps:
- Open your course
- Click on Settings in the course menu (last menu item)
- Choose the Navigation tab at the top of the page
All the items in the upper table will appear on the menu. You can hide a menu item by dragging it below the indicated line to the second table.
The reverse is also true. Click and drag any menu item to the above table and place it in the order you want.
For more information, here are 2 guides from Canvas: