Braintree

import { Braintree, ApplePayOptions, PaymentUIOptions } from '@ionic-native/braintree/ngx';

constructor(private braintree: Braintree) { }

...

// Your Braintree `Tokenization Key` from the Braintree dashboard.
// Alternatively you can also generate this token server-side
// using a client ID in order to allow users to use stored payment methods.
// See the [Braintree Client Token documentation](https://developers.braintreepayments.com/reference/request/client-token/generate/node#customer_id) for details.
const BRAINTREE_TOKEN = '<YOUR_BRAINTREE_TOKEN>';

// NOTE: Do not provide this unless you have configured your Apple Developer account
// as well as your Braintree merchant account, otherwise the Braintree module will fail.
const appleOptions: ApplePayOptions = {
  merchantId: '<YOUR MERCHANT ID>',
  currency: 'USD',
  country: 'US'
}

const paymentOptions: PaymentUIOptions = {
  amount: '14.99',
  primaryDescription: 'Your product or service (per /item, /month, /week, etc)',
}

this.braintree.initialize(BRAINTREE_TOKEN)
  .then(() => this.braintree.setupApplePay(appleOptions))
  .then(() => this.braintree.presentDropInPaymentUI(paymentOptions))
  .then((result: PaymentUIResult) => {
    if (result.userCancelled) {
      console.log("User cancelled payment dialog.");
    } else {
      console.log("User successfully completed payment!");
      console.log("Payment Nonce: " + result.nonce);
      console.log("Payment Result.", result);
    }
  })
  .catch((error: string) => console.error(error));