The “To-do list” tutorial opens with
In this 3-part tutorial learn how to build a to-do list block that shows a
list of tasks from a table and allows you to check them off when done.
The supporting screen recording demonstrates this functionality.
However, the tutorial only covers displaying the contents of a table or view.
There is no information on modifying the table (via a checkbox or otherwise).
A subsequent guide does discuss writing to a table though it’s not in terms of
the “to-do list” block.