Why is My RN Turbo Modules Package 'null'

Question

Following the Android Turbo Modules in the documentation see here to a tee, I see the following error when I try to use it in my react-native code:

'Cannot read property 'add' of null, js engine: hermes'

I have fabric enabled and hermes enabled. I'm using RN 0.72.6. Does anyone experience the same thing when they go through the documented guide?

I was expecting to be able to use the package in my React Native app to perform an addition, but instead, the library was null.

What's interesting is that in both my CalculatorModule and CalculatorPackage files, I have an error :'Unresolved reference: facebook'

Please see the code below

Here's my folder structure: RTNCalculator folder structure

CalculatorModule.kt

package com.rtncalculator

import com.facebook.react.bridge.Promise
import com.facebook.react.bridge.ReactApplicationContext
import com.rtncalculator.NativeCalculatorSpec

class CalculatorModule(reactContext: ReactApplicationContext) : NativeCalculatorSpec(reactContext) {

  override fun getName() = NAME

  override fun add(a: Double, b: Double, promise: Promise) {
    promise.resolve(a + b)
  }

  companion object {
    const val NAME = "RTNCalculator"
  }
}

CalculatorPackage.kt

package com.rtncalculator;

import com.facebook.react.TurboReactPackage
import com.facebook.react.bridge.NativeModule
import com.facebook.react.bridge.ReactApplicationContext
import com.facebook.react.module.model.ReactModuleInfo
import com.facebook.react.module.model.ReactModuleInfoProvider

class CalculatorPackage : TurboReactPackage() {
 override fun getModule(name: String?, reactContext: ReactApplicationContext): NativeModule? =
   if (name == CalculatorModule.NAME) {
     CalculatorModule(reactContext)
   } else {
     null
   }

 override fun getReactModuleInfoProvider() = ReactModuleInfoProvider {
   mapOf(
     CalculatorModule.NAME to ReactModuleInfo(
       CalculatorModule.NAME,
       CalculatorModule.NAME,
       false, // canOverrideExistingModule
       false, // needsEagerInit
       true, // hasConstants
       false, // isCxxModule
       true // isTurboModule
     )
   )
 }
}

build.gradle

buildscript {
  ext.safeExtGet = {prop, fallback ->
    rootProject.ext.has(prop) ? rootProject.ext.get(prop) : fallback
  }
  repositories {
    google()
    gradlePluginPortal()
  }
  dependencies {
    classpath("com.android.tools.build:gradle:7.3.1")
    classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:1.7.22")
  }
}

apply plugin: 'com.android.library'
apply plugin: 'com.facebook.react'
apply plugin: 'org.jetbrains.kotlin.android'

android {
  compileSdkVersion safeExtGet('compileSdkVersion', 33)
  namespace "com.rtncalculator"
}

repositories {
  mavenCentral()
  google()
}

dependencies {
  implementation 'com.facebook.react:react-native'
}

js/NativeCalculator.ts

import type {TurboModule} from 'react-native/Libraries/TurboModule/RCTExport';
import {TurboModuleRegistry} from 'react-native';

export interface Spec extends TurboModule {
  add(a: number, b: number): Promise<number>;
}

export default TurboModuleRegistry.get<Spec>('RTNCalculator') as Spec | null;

package.json

{
  "name": "rtn-calculator",
  "version": "0.0.1",
  "description": "Add numbers with Turbo Native Modules",
  "react-native": "js/index",
  "source": "js/index",
  "files": [
    "js",
    "android",
    "ios",
    "rtn-calculator.podspec",
    "!android/build",
    "!ios/build",
    "!**/__tests__",
    "!**/__fixtures__",
    "!**/__mocks__"
  ],
  "keywords": [
    "react-native",
    "ios",
    "android"
  ],
  "repository": "https://github.com/<your_github_handle>/rtn-calculator",
  "author": "<Your Name> <your_email@your_provider.com> (https://github.com/<your_github_handle>)",
  "license": "MIT",
  "bugs": {
    "url": "https://github.com/<your_github_handle>/rtn-calculator/issues"
  },
  "homepage": "https://github.com/<your_github_handle>/rtn-calculator#readme",
  "devDependencies": {},
  "peerDependencies": {
    "react": "*",
    "react-native": "*"
  },
  "codegenConfig": {
    "name": "RTNCalculatorSpec",
    "type": "modules",
    "jsSrcsDir": "js",
    "android": {
      "javaPackageName": "com.rtncalculator"
    }
  }
}