PaymentManager constructor
PaymentManager()
Implementation
PaymentManager() {
_razorPay = Razorpay()
..on(Razorpay.EVENT_PAYMENT_SUCCESS, _handlePaymentSuccess)
..on(Razorpay.EVENT_PAYMENT_ERROR, _handlePaymentError)
..on(Razorpay.EVENT_EXTERNAL_WALLET, _handleExternalWallet);
// _checkoutPro = PayUCheckoutProFlutter(PaymentManager as PayUCheckoutProProtocol);
}