Ionic 3 app crash on tap PayPal pay button

I created an ionic app. And install ionic native PayPal. Link->

The app running in android smoothly with no issues. But when comes to ios the app crash with the following error.

Please help me out.
Thank you


So what should i do…now can u please help me.
Thank you @yuhai2017


Same things happen in real device testing… @yuhai2017