In order to add Sodium as a dependency, you must first create a Swift package. Then in the newly created Package.swift, open it and add Sodium as a dependency
import PackageDescription
let package = Package(
name: "yourswiftexecutablehere",
dependencies: [
.Package(url: "https://github.com/Azoy/Sodium", majorVersion: 1)
]
)
Documentation can be found here: https://download.libsodium.org/doc/