How to properly use datePipe in Angular

Question

It's been a few hours that I'm trying to figure this out. I'm trying to simply convert a timestamp Timestamp(seconds=1555755972, nanoseconds=393000000) into a normal date dd/mm/yyyy.

I'm getting a list of documents from firestore, then I pass them through my component:

export class MissionComponent implements OnInit {

  missions: Mission[];
  mission: any = {};

  constructor(
      private missionService: MissionService,
      private datePipe: DatePipe)
 {}

  ngOnInit() {
    this.missionService.getMissions().subscribe(data => {
      this.missions = data.map(e => {
        return{
          id: e.payload.doc.id,
          ...e.payload.doc.data()
        } as Mission;
      });
    });
}

and then I show few fileds thorugh a for cycle in the html:

<tr *ngFor="let mission of missions">
                                            ..
                                            <td>{{mission.dataRitiro.toDate() }}</td>
                                            <td>{{mission.dataConsegna.toDate() }}</td>
...

mission.dataRitiro gives me Timestamp(seconds=1555755972, nanoseconds=393000000)

If I'm converting the mission.dataRitiro with .toDate() I'm getting Wed Apr 03 2019 00:00:00 GMT+0200 (Ora legale dell’Europa centrale)

untill here everithing works, but I want to get 03/04/2019, so, searching in internet I've found the method datePipe, I just need to write mission.dataRitiro.toDate() | date: 'dd/mm/yyyy' but if I wirte it inside the html I just get a blank field and in console I'm getting this error

Error: InvalidPipeArgument: 'Missing locale data for the locale "it-IT".' for pipe 'DatePipe'
    at...

but in my app.module I've imported import { NgModule, LOCALE_ID } from '@angular/core'; and inserted inside the providers { provide: LOCALE_ID, useValue: "it-IT" }

So at this point I really don't know what to do. Thankyou guys.