This bonus geocache is NOT at the posted coordinates.
First, you will need the Adventure Lab app available from the app store on your smartphone.
https://adventurelab.page.link/vz2h
You will then need to complete the "National Treasure" Adventure Lab in order to get the final coordinates and physical container.
You will have 5 stops to complete before you receive the coordinates.
The difficulty rating of this cache reflects the additional legwork required to unlock the final coordinates, actual hide difficulty is 1.5.