How to pass variables from .ts to html

I am using the Hero demo provided from the angular website. I modified it to keep the data in the rest of the server. That's ok, but when I try to open the hero's details it misses printing every detail like last name ecc...

I think there is a problem between "hero-detail.component.ts" and "hero-detail.component.html".

When I try to print this.hero.nome, it shows nothing, so I think that's an empty class.

My rest server confirmed that it sent all the information correctly.

Here is my hero-detail.component.ts

import { Component, OnInit, Input } from '@angular/core';
import { ActivatedRoute } from '@angular/router';
import { Location } from '@angular/common';

import { Hero }         from '../hero';
import { HeroService }  from '../hero.service';

@Component({
  selector: 'app-hero-detail',
  templateUrl: './hero-detail.component.html',
  styleUrls: [ './hero-detail.component.css' ]
})
export class HeroDetailComponent implements OnInit {
  @Input() hero: Hero;



  constructor(
    private route: ActivatedRoute,
    private heroService: HeroService,
    private location: Location
  ) {}

  ngOnInit(): void {
    this.getHero();
  }

  getHero(): void {
    const id = +this.route.snapshot.paramMap.get('id');
    this.heroService.getHero(id)
    .subscribe(hero => this.hero = hero);

  }

  goBack(): void {
    this.location.back();
  }

 save(): void {
    this.heroService.updateHero(this.hero)
      .subscribe(() => this.goBack());
  }
}

and my hero-detail.component.html

<div *ngIf="hero">

  <h2>{{hero.nome | uppercase}} Dettagli</h2>
  <div><span>id: </span>{{hero.id}}</div>
  <div>
    <label>Nome:
      <input [(ngModel)]="hero.nome" placeholder="Nome"/>

      {{hero.nome}}
    </label>
    </div>
    <div>
    <label >Cognome:
      <input [(ngModel)]="hero.cognome" placeholder="Cognome"/>
    </label>
  </div>



  <button (click)="goBack()">go back</button>
  <button (click)="save()">save</button>
</div>

In the HTML file I want to display the first and last name of the hero provided by my rest server