Ionic3 native paypal init error

I am doing an integration between my ionic3 app and Paypal, I am following the doc from official ionic native paypal plugin website. But when I press the button to trigger the paypal, it refresh to the root page of the app.

Here is my code:

gotoPaypal(){
this.pppayment = new PayPalPayment('3.33', 'USD', 'Description', 'sale');
this.payPal.init({
PayPalEnvironmentProduction: 'dgdfghfjfhgjghjadsasfdsdfsghkgjkjhk',
PayPalEnvironmentSandbox: 'hasvahgsdvajbdhgvcasdh sahgdvasdvagksd'
}).then(() => {
   this.payPal.prepareToRender('PayPalEnvironmentSandbox', new PayPalConfiguration({
   })).then(() => {
      this.payPal.renderSinglePaymentUI(this.pppayment).then(() => {
      }, () => {
         console.log("Paypal 3333");
      });
   }, () => {
      console.log("Paypal 2222");      
   });
 }, () => {
    console.log("Paypal 1111");
});
}

And before it’s auto refresh, I see console printed “Paypal 1111”, so I think init Paypal have error, Anyone know what happen or how to fix?