Show alert in a specific page for first time

Ionic Framework ionic-v3
1

how to show alert in a HomePage page for first time during app start. if checkbox is checked then i’ll keep value in storage and this alert will not never come (it’s working). but if not checked then this alert will show next app start. at present, when i enter this page 2nd time this alert is coming. how will i do this?

ionViewDidLoad(){
	Promise.all([this.storage.get("DateFormat")  ]).then(values => {
		console.log(values[0]); 
		if(values[0]==''){
			this.doCheckbox();
		}
		
	});
}
doCheckbox() {
	let alert = this.alertCtrl.create();
	alert.setTitle('Attention');
	alert.setSubTitle('Sub title here');
	alert.addInput({
	  type: "checkbox",
	  label: "Don't show this message again",
	  value: 1
	});
	alert.addButton({
	  text: 'Ok',
	  handler: data => {
		this.storage.set('DateFormat', data);
	  }
	});
	alert.setMode("md");
	alert.present();
}