Summit patio door model 6068 lock

Hello Team,
I recently bought a shed from Home depot (Tuff Shed), and the only door I included has been a sliding door, which unfortunately came without key lock (= you cannot lock from outside - no keyhole, you can lock the door only from inside by switching a little lever). on the outside handle there there is what look a predefined location for the keyhole, so I guess it would be possible to replace the handle with one including the keyhole.

The brand is SUMMIT Patio doors, and the model is 6068.
Can you please help, as Tuff Shed stated their sliding doors are supposed to locked only from inside (so how someone can lock its shed?)

Happy Thanksgiving!
Best regards,
Daniele