test/tab3.page.ts

import { Component } from '@angular/core';
import { ToastController } from '@ionic/angular';

@Component({
  selector: 'app-tab3',
  templateUrl: 'tab3.page.html',
  styleUrls: ['tab3.page.scss']
})
export class Tab3Page {

  constructor(private toastController: ToastController) {}

  async onItemClick(item: string) {
    const toast = await this.toastController.create({
      message: `Clicked on ${item}`,
      duration: 2000,
    });
    toast.present();
  }

}