How to make a certain tab active when app loads

i want is when a my loads first time the dashboard page has three tabs.From these three on of the tab should be active. but i don’t know how to make that happen.

my tab-bar code :

<ion-tabs>
    <ion-tab-bar slot="bottom">
      <ion-tab-button tab="explore">
      <ion-icon  src="../../assets/no upcoming ride/icon-explore@3x.svg"></ion-icon>
        <ion-label>Explore</ion-label>
      </ion-tab-button>
      <span class="border-left"></span>
      <ion-tab-button tab="suggested" class="tab-btn2">
        <ion-icon src="../../assets/no upcoming ride/icon-suggested@3x.svg"></ion-icon>
        <ion-badge>1</ion-badge>
        <ion-label>Suggested</ion-label>
      </ion-tab-button>
      <span class="border-right"></span>
      <ion-tab-button tab="upcoming">
        <ion-icon src="../../assets/no upcoming ride/icon-upcoming@3x.svg"></ion-icon>
        <ion-label>Upcoming</ion-label>
        <ion-badge>2</ion-badge>
      </ion-tab-button>
    </ion-tab-bar>
  </ion-tabs>

my ionic info :
Ionic:

Ionic CLI : 6.9.3 (C:\Users\faizan\AppData\Roaming\npm\node_modules@ionic\cli)
Ionic Framework : @ionic/angular 5.0.7
@angular-devkit/build-angular : 0.803.26
@angular-devkit/schematics : 8.3.26
@angular/cli : 8.3.26
@ionic/angular-toolkit : 2.2.0

Capacitor:

Capacitor CLI : 1.5.2
@capacitor/core : 1.5.2

Cordova:

Cordova CLI : not installed
Cordova Platforms : android 8.1.0
Cordova Plugins : cordova-plugin-ionic-keyboard 2.2.0, cordova-plugin-ionic-webview 4.1.3, (and 8 other plugins)

Utility:

cordova-res : 0.9.0
native-run : 0.3.0

System:

NodeJS : v12.16.1 (C:\Program Files\nodejs\node.exe)
npm : 6.14.4
OS : Windows 10

have a look this link

> use [selectedIndex]='index number' for <ion-tabs>

kindly explain in detail as iam new in ionic