Ok, so I managed to fix this by adding dependency to my target.
Here's the update Package.swift
// swift-tools-version: 5.10
// The swift-tools-version declares the minimum version of Swift required to build this package.
let package = Package(
name: "MyPackage",
platforms: [.iOS(.v16), .macCatalyst(.v16), .macOS(.v14)],
products: [.library(name: "MyPackage", targets: ["MyPackage"]),],
dependencies: [
.package(path: "../external-package")
], targets: [
.target(
name: "MyPackage",
dependencies: [
👉❗️ .product(name: "ExternalPackageName", package: "external-package")
],
path: "Sources"
),
.testTarget(name: "MyPackageTests", dependencies: ["MyPackage"]),
]
)