How to integrate Easypaisa with react-native

gistfile1.txt

Add 3 packages :

import AesJs from 'aes-js';
import { Buffer } from 'buffer';
import queryString, { stringify } from 'query-string';

// Generating bytes encryption in AES, ECB mode with easypaisa HashKey
const aes = new AesJs.ModeOfOperation.ecb(AesJs.utils.utf8.toBytes(APP_STRING.HASH_KEY));

function pkcs5Pad(text: string, blockSize: number): string {
  const pad = blockSize - (text.length % blockSize);
  return text + String.fromCharCode(pad).repeat(pad);
}

// converting object to string with assending order
function convertObjectToString(obj: any): string {
  let data = '';
  Object.keys(obj)
    .sort()
    .forEach((key) => {
      data += `${key}=${obj[key]}` + '&';
    });
  return data.slice(0, data.length - 1);
}

// Generating HashMapReq
    const hasMapReq = Buffer.from(aes.encrypt(Buffer.from(pkcs5Pad(convertObjectToString(requestBody), 16)))).toString(
      'base64',
    );

appending hashMapReq with request body

   requestBody['merchantHashedReq'] = hasMapReq;

Here is webView Setting

<WebView
        source={{
          uri: requestURL,
          headers: requestHeader,
          body: requestBodyParams,
          method: 'POST',
        }}
        onNavigationStateChange={(e) => navigationURL(e)}
        javaScriptEnabled
        startInLoadingState
        scalesPageToFit
        onMessage={(e) => console.log('Click', e)}
      />