Request location on the Apple Watch only, without code on the paired phone

Question

I've looked everywhere including Apple's sample app. But I can't find anywhere when I can request location without needing any code running on the phone, the below code when used in an 'interface controller' returns a "not determined" status. I did check that my info.plist has the privacy key values set.

import Foundation
import CoreLocation

class LocationManager: NSObject, CLLocationManagerDelegate {

    /// Location manager to request authorization and location updates.
    let manager = CLLocationManager()

    /// Flag indicating whether the manager is requesting the user's location.
    var isRequestingLocation = false

      var workoutLocation: CLLocation?

    func requestLocation() {

        guard !isRequestingLocation else {
            manager.stopUpdatingLocation()
            isRequestingLocation = false
            return
        }

        let authorizationStatus = CLLocationManager.authorizationStatus()

        switch authorizationStatus {
        case .notDetermined:
            isRequestingLocation = true
            manager.requestWhenInUseAuthorization()

        case .authorizedWhenInUse:
            isRequestingLocation = true
            manager.requestLocation()

        case .denied:
            print("Location Authorization Denied")
        default:
            print("Location AUthorization Status Unknown")
        }
    }

    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        guard !locations.isEmpty else { return }

        DispatchQueue.main.async {
            let lastLocationCoordinate = locations.last!.coordinate

            print("Lat =  \(lastLocationCoordinate.latitude)")

            print("Long = \(lastLocationCoordinate.longitude)")

            self.isRequestingLocation = false

        }
    }
}

Main App info.plist

<key>NSLocationAlwaysUsageDescription</key>
    <string>We will read your location while performing a workout to create a workout route</string>
    <key>NSLocationUsageDescription</key>
    <string>We will read your location while performing a workout to create a workout route</string>
    <key>NSLocationWhenInUseUsageDescription</key>
    <string>We will read your location while performing a workout to create a workout route</string>

Watch Extension info.plist

<key>NSLocationAlwaysUsageDescription</key>
    <string>We will read your location while performing a workout to create a workout route</string>
    <key>NSLocationUsageDescription</key>
    <string>We will read your location while performing a workout to create a workout route</string>
    <key>NSLocationWhenInUseUsageDescription</key>
    <string>We will read your location while performing a workout to create a workout route</string>

Answer 1

As of watchOS 6.0/ Xcode 11, this is now possible. To enable it, the watch extension target must have the box checked for Supports running without iOS App installation

After checking this setting and rebuilding, my requestWhenInUseAuthorization call showed the prompt on the watch face as expected.