How Do I get all localstorage keys in order and display them in text?

How Do I get all localstorage keys in order and display them in text? Im trying to make a game with different levels for a different star based on your time.I cant figure out how to set them though

from the manual:

"Get all key names"

Retrieve a list of all the key names that currently exist in storage. This triggers "On all key names loaded" when the list has been loaded, where the KeyCount and KeyAt expressions can be used to access the list.

another option would be to store all the data in an array, and then just save the array to local storage so there is only one key to set and get.