Please follow this steps and import the widgets examples https://help.qlik.com/en-US/sense-developer/3.1/Subsystems/Extensions/Content/Widget/widgets-example-library.htm#anchor-…
And open Widget editor then library and connect to an app in widget editor.
In right corner you will find a edit option ,
i am using the "Formatted table with the Tile" Example and Sorting is showing up in the Available components just drag drop that.
Hope this helps,