Yor app.module.ts should look like this in Ionic 3.X
...
import { HttpModule } from '@angular/http';
...
imports: [
BrowserModule,
HttpModule,
IonicModule.forRoot(MyApp)
],
And then you can import the Http Module in your provider
import { Http } from '@angular/http';
....
constructor(private http: Http) { }
You can follow my Ionic 3 guide here: Guide: How to update to Ionic 3.X