Can't set "import rotation" in asset from store

i am using an asset called “military weapons dark” and there is a mesh that i need to rotate

i try to reimport the mesh after changing the rotation but it asks me for the path which i can’t find…

below the rotation option it says Source file: “…/…/FBX/Pistols_B.FBX” but i can’t seem to find where this fbx is.

i tried exporting the asset and then using that exported file as the path to reimport the mesh, the rotation works but it breaks all the animations

i also need to rotate all the animations