How To Set SetCancelable(false) In Ionic App?

I want to disable auto cancel in alert dialog but I do n't know, I searched about it, I want like android studio:

builder.setCancelable(false);

work, please help me.

On ionic 3 set enableBackdropDismiss to false

   let alert = this.alertController.create({
    title: 'Alert',
    subTitle: 'Subtitle',
    message: 'This is a test.',
    enableBackdropDismiss:false
  });

  alert.present();

On ionic 4 set backdropDismiss to false

 const alert = await this.alertController.create({
  header: 'Alert',
  backdropDismiss: false,
  subHeader: 'Subtitle',
  message: 'This is a test.',

 });

 await alert.present();