Save and Continue Later: How to enable it

I'm trying to figure out how users can "Save and Continue Later" Is that a button I need to add to my form?

There is two ways to enable Save Forms and Continue later:

1) The session method (Stores data up to one month)

How-to-Save-Forms-and-Continue-Later

2) The autofill method (Stores data up to one day)

How-to-Enable-Auto-Fill-on-Forms