Cannot find module '#ionic-native/power-management/ngx' - ionic-framework

Question

I installed cordova power management plugin into my ionic application. Following the usage guidance "https://ionicframework.com/docs/native/power-management#installationenter link description here", I import the class as below:
import { PowerManagement } from '#ionic-native/power-management/ngx';
but, when build this ionic app, got the error:
Cannot find module '#ionic-native/power-management/ngx'
Why this error appears? How to fix it?
I try to import the class with removing the ngx module, then error disappears:
import { PowerManagement } from '#ionic-native/power-management';
my package.json file is:
{
"name": "ionicapp",
"version": "0.0.1",
"author": "Ionic Framework",
"homepage": "http://ionicframework.com/",
"private": true,
"scripts": {
"start": "ionic-app-scripts serve",
"clean": "ionic-app-scripts clean",
"build": "ionic-app-scripts build",
"lint": "ionic-app-scripts lint"
},
"dependencies": {
"#angular/animations": "5.2.11",
"#angular/common": "5.2.11",
"#angular/compiler": "5.2.11",
"#angular/compiler-cli": "5.2.11",
"#angular/core": "^5.2.11",
"#angular/forms": "5.2.11",
"#angular/http": "5.2.11",
"#angular/platform-browser": "5.2.11",
"#angular/platform-browser-dynamic": "5.2.11",
"#angular/router": "^6.1.9",
"#ionic-native/background-geolocation": "^4.16.0",
"#ionic-native/background-mode": "^4.20.0",
"#ionic-native/ble": "^4.12.0",
"#ionic-native/bluetooth-serial": "^4.12.2",
"#ionic-native/camera": "4.3.3",
"#ionic-native/core": "^4.12.2",
"#ionic-native/geolocation": "^4.12.0",
"#ionic-native/google-maps": "^4.12.0",
"#ionic-native/launch-navigator": "^4.15.0",
"#ionic-native/native-storage": "^4.12.0",
"#ionic-native/network": "^4.12.2",
"#ionic-native/network-interface": "^4.12.2",
"#ionic-native/power-management": "^4.20.0",
"#ionic-native/splash-screen": "~4.11.0",
"#ionic-native/sqlite": "^4.12.2",
"#ionic-native/status-bar": "^4.11.0",
"#ionic/storage": "^2.1.3",
"#ngx-translate/core": "8.0.0",
"#ngx-translate/http-loader": "^2.0.0",
"#types/google-maps": "^3.2.0",
"#types/googlemaps": "^3.30.12",
"an": "0.0.8",
"angularfire2": "^5.0.2",
"chart.js": "^2.7.2",
"cordova-android": "7.1.0",
"cordova-plugin-actionsheet": "^2.3.3",
"cordova-plugin-background-mode": "git+https://github.com/tushe/cordova-plugin-background-mode.git",
"cordova-plugin-ble-central": "^1.2.2",
"cordova-plugin-bluetooth-serial": "^0.4.7",
"cordova-plugin-compat": "^1.2.0",
"cordova-plugin-device": "^2.0.2",
"cordova-plugin-dialogs": "^2.0.1",
"cordova-plugin-geolocation": "^4.0.1",
"cordova-plugin-googlemaps": "^2.4.2",
"cordova-plugin-ionic-keyboard": "^2.1.2",
"cordova-plugin-ionic-webview": "^2.1.0",
"cordova-plugin-mauron85-background-geolocation": "^3.0.0-alpha.43",
"cordova-plugin-nativestorage": "^2.3.2",
"cordova-plugin-network-information": "^2.0.1",
"cordova-plugin-networkinterface": "^2.0.0",
"cordova-plugin-powermanagement-orig": "^1.1.2",
"cordova-plugin-splashscreen": "^5.0.2",
"cordova-plugin-statusbar": "^2.4.2",
"cordova-plugin-whitelist": "^1.3.3",
"cordova-sqlite-storage": "^2.4.0",
"firebase": "^5.5.3",
"ionic-angular": "3.9.2",
"ionic-native": "4.1.1",
"ionicons": "3.0.0",
"ng2-charts": "^1.6.0",
"rxjs": "5.5.11",
"sw-toolbox": "3.6.0",
"uk.co.workingedge.phonegap.plugin.launchnavigator": "^4.2.2",
"zone.js": "0.8.26",
"at.gofg.sportscomputer.powermanagement": "~1.1.2"
},
"devDependencies": {
"#ionic/app-scripts": "^3.2.0",
"#mauron85/cordova-plugin-background-geolocation": "^3.0.0-alpha.4",
"typescript": "~2.6.2"
},
"description": "An Ionic project",
"cordova": {
"plugins": {
"cordova-plugin-ble-central": {},
"cordova-plugin-whitelist": {},
"cordova-plugin-device": {},
"cordova-plugin-splashscreen": {},
"cordova-plugin-ionic-webview": {},
"cordova-plugin-ionic-keyboard": {},
"cordova-plugin-geolocation": {
"GEOLOCATION_USAGE_DESCRIPTION": "To locate you"
},
"cordova-plugin-mauron85-background-geolocation": {
"GOOGLE_PLAY_SERVICES_VERSION": "11+",
"ANDROID_SUPPORT_LIBRARY_VERSION": "23+",
"ALWAYS_USAGE_DESCRIPTION": "App requires background tracking enabled",
"MOTION_USAGE_DESCRIPTION": "App requires motion detection"
},
"cordova-plugin-nativestorage": {},
"cordova-sqlite-storage": {},
"cordova-plugin-statusbar": {},
"cordova-plugin-bluetooth-serial": {},
"cordova-plugin-network-information": {},
"cordova-plugin-networkinterface": {},
"uk.co.workingedge.phonegap.plugin.launchnavigator": {
"OKHTTP_VERSION": "3.+"
},
"cordova-plugin-background-mode": {},
"at.gofg.sportscomputer.powermanagement": {}
},
"platforms": [
"android"
]
}
}

Answer 1

Use ngx if your Angular version is >=6
You seem to be using the wrong plugin version. Correct your error by following the steps mentioned below
Check your project type in ionic.config.json file.
If the type is "ionic-angular", then install 4 version.
ionic cordova plugin add cordova-plugin-powermanagement-orig
npm install #ionic-native/power-management#4
If the type is "angular", then install the latest version
ionic cordova plugin add cordova-plugin-powermanagement-orig
npm install #ionic-native/power-management
Note:
Add ngx at the end of import only if you are using Angular 6 or 6+
import { PowerManagement } from '#ionic-native/power-management/ngx';
if not remove ngx from the import both in app.module.ts and app.component.ts
import { PowerManagement } from '#ionic-native/power-management';
Refencence:https://github.com/ionic-team/ionic/issues/15225#issuecomment-414074074