How does Game Kit offline leaderboard submission work?

I do not understand how offline leaderboard submission is supposed to work in Game Kit:

While the documentation briefly states that offline submission is supported, how is that even possible when you first have to fetch a leaderboard object in order to then call its submitScore function? How can I get the leaderboard object in the first place when offline?

Can anyone enlighten me how this works? Or maybe point me to some relevant documentation?

How does Game Kit offline leaderboard submission work?
 
 
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