The To-Do Checklist can be accessed by clicking on the To-Do button.
This will open a tab in any project window you are currently on, similar to the Outline tab on the Notecards screen.
At the bottom of the tab, you can click on the Add button to create a new To-Do on your checklist.
These To-Dos cannot be linked to notecards or citations. You can add a Due Date, but that is optional. The To-Do will highlight red when incomplete.