Ion-select loads form

Good night, I'm doing a page in my ionic app and I want that, when I select an ion-select option, the page loads a form, I'm using ngif but I can not follow the code:

(ts)

  todos: Observable<any>;
  tipo: any = [
    {tipos: 'Debito'},
    {tipos: 'Credito'}
  ];
  selectedTipo: any[] = this.tipo[1];
  change = false;
  secondChange = false;


  constructor(public navCtrl: NavController, public navParams: NavParams, public todoService: TodoService, public alertCtrl: AlertController, public toastCtrl: ToastController) {
    this.loadTodos();
  }
  pageSelect(tipoTipos, tipoValue){
    console.log(tipoTipos);
    this.selectedTipo = tipoTipos;
  }

  debitOn(){
    console.log('Teste1')
  }

  creditOn(){
    console.log('teste2')
  }

(html)

<ion-content padding>
  <ion-item>
    <ion-label>Tipo de transação</ion-label>
    <ion-select name="selectedTipo" ngModel (ngModelChange)="pageSelect($event, tipo.tipos, tipo.value)">
      <ion-option value="" disabled>Escolha o tipo</ion-option>
      <ion-option *ngFor="let t of tipo" [value]="tipo.tipos">
        {{t.tipos}}
      </ion-option>
    </ion-select>
  </ion-item>
  <!-- form de debitos -->
  <div *ngIf="change; then debitOn"></div>
  <!-- <ng-template #debitOn></ng-template> -->
  <!-- form de creditos -->
  <div *ngIf="secondChange; then creditOn"></div>
  <!-- <ng-template #creditOn></ng-template> -->
</ion-content>