Close popover with BackButton

Hello,

I don’t know how to do it…

I have this, in app.component.ts to handle the BackButton in the App but don’t know how to detect and close from here the Popover

this.platform.registerBackButtonAction(() => {
        console.log('BackButtonAction');
        if (this.nav.length() == 1) {
            if (!this.showedAlert) {
                this.confirmExitApp();
            } else {
                this.showedAlert = false;
                this.confirmAlert.dismiss();
            }
        }
 else {
        this.nav.pop({});
      }   

Thanks for you answers.