IONIC 3 Error: Could not find an "NgModule" decorator in app.module.ts

I am getting following error while running this command in my ionic 3 Project

[app-scripts] [01:08:19] ionic-app-script task: "serve"
[app-scripts] [01:08:19] Error: Could not find an "NgModule" decorator in
[app-scripts] /Users/user/Documents/ios-full-project/src/app/app.module.ts
[app-scripts] Error: Could not find an "NgModule" decorator in /Users/user/Documents/ios-full-project/src/app/app.module.ts
[app-scripts] at new BuildError (/Users/user/Documents/ios-full-project/node_modules/@ionic/app-scripts/dist/util/errors.js:16:28)
[app-scripts] at /Users/user/Documents/ios-full-project/node_modules/@ionic/app-scripts/dist/deep-linking.js:57:21

[ERROR] ionic-app-scripts has unexpectedly closed (exit code 1).



Here is my environment

Ionic:

Ionic CLI : 6.19.0 (/Users/user/.nvm/versions/node/v14.21.3/lib/node_modules/@ionic/cli) Ionic Framework : ionic-angular 3.9.5 @ionic/app-scripts : 3.2.3

Cordova:

Cordova CLI : not installed Cordova Platforms : not available Cordova Plugins : not available

Utility:

cordova-res (update available: 0.15.4) : 0.13.1 native-run (update available: 2.0.1) : 1.7.4

System:

ios-deploy : 1.12.2 ios-sim : ios-sim/9.0.0 darwin-x64 node-v14.21.3 NodeJS : v14.21.3 (/Users/user/.nvm/versions/node/v14.21.3/bin/node) npm : 6.14.18 OS : macOS Unknown Xcode : Xcode 16.2 Build version 16C5032a

Continue reading...