Dismiss Ionic 4 popover from its component

add private popoverController: PopoverController to the component constructor

then write a function like this and call it when you want to dismiss the modal

 async DismissClick() {
await this.popoverController.dismiss();
  }

I solved this problem as follows: In parent component I have passed callback as prop to child component:

const popover = await this.popoverController.create({
  component: PopoverComponent,
  event: ev,
  componentProps: {
    onClick: () => {
      popover.dismiss();
    },
  },
});
await popover.present();

And in PopoverComponent I have added @Input() onClick; which called when the user clicks:

...
@Input()
public onClick = () => {}
...
afterClick() {
  this.onClick();
}