In a text block: type +timestamp and hit enter.
Then option click on the timestamp...
...to change the time using the date picker.
Alternative formulation of the question:
How can I create a table of contents in Capacities?
You do not need to create a table of contents manually. If you use headings, an automatic one is created for you and available in the right sidebar!
General
General questions about Capacities including device support, languages, and staying updated.