why high charts export server not works after upgrade node 14 to 20

  "exports": {
    ".": {
      "import": "./dist/index.esm.js",
      "require": "./dist/index.cjs"
    }
  },
  "repository": {
    "url": "https://github.com/highcharts/node-export-server",
    "type": "git"
  },
  "bin": {
    "highcharts-export-server": "./bin/cli.js"
  },
  "scripts": {
    "install": "node install.js",
    "start": "nodemon index.js",
    "test": "echo \"Error: no test specified\" && exit 1"
  },

# Export config
EXPORT_DEFAULT_TYPE = png
EXPORT_DEFAULT_CONSTR = chart
EXPORT_DEFAULT_HEIGHT = 400
EXPORT_DEFAULT_WIDTH = 600
EXPORT_DEFAULT_SCALE = 1
EXPORT_RASTERIZATION_TIMEOUT = 1500

# Highcharts config
HIGHCHARTS_VERSION = latest
HIGHCHARTS_CDN = https://code.highcharts.com/
HIGHCHARTS_FORCE_FETCH = false
HIGHCHARTS_CORE_SCRIPTS =
HIGHCHARTS_MODULES =
HIGHCHARTS_INDICATORS =

# Custom code config
HIGHCHARTS_ALLOW_CODE_EXECUTION = false
HIGHCHARTS_ALLOW_FILE_RESOURCES = false

# Server config
HIGHCHARTS_SERVER_ENABLE = false
HIGHCHARTS_SERVER_HOST = 0.0.0.0
HIGHCHARTS_SERVER_PORT = 7801

# Server SSL config
HIGHCHARTS_SERVER_SSL_ENABLE = false
HIGHCHARTS_SERVER_SSL_FORCE = false
HIGHCHARTS_SERVER_SSL_PORT = 443
HIGHCHARTS_SERVER_SSL_CERT_PATH =

# Server rate limiting config
HIGHCHARTS_RATE_LIMIT_ENABLE = false
HIGHCHARTS_RATE_LIMIT_MAX = 10
HIGHCHARTS_RATE_LIMIT_WINDOW = false
HIGHCHARTS_RATE_LIMIT_DELAY = 0
HIGHCHARTS_RATE_LIMIT_TRUST_PROXY = false
HIGHCHARTS_RATE_LIMIT_SKIP_KEY =
HIGHCHARTS_RATE_LIMIT_SKIP_TOKEN =

# Pool config
HIGHCHARTS_POOL_MIN_WORKERS = 8
HIGHCHARTS_POOL_MAX_WORKERS = 8
HIGHCHARTS_POOL_WORK_LIMIT = 40
HIGHCHARTS_POOL_ACQUIRE_TIMEOUT = 5000
HIGHCHARTS_POOL_CREATE_TIMEOUT = 5000
HIGHCHARTS_POOL_DESTROY_TIMEOUT = 5000
HIGHCHARTS_POOL_IDLE_TIMEOUT = 30000
HIGHCHARTS_POOL_CREATE_RETRY_INTERVAL = 200
HIGHCHARTS_POOL_REAPER_INTERVAL = 1000
HIGHCHARTS_POOL_BENCHMARKING = false
HIGHCHARTS_POOL_LISTEN_TO_PROCESS_EXITS = true

# Logging config
HIGHCHARTS_LOG_LEVEL = 4
HIGHCHARTS_LOG_FILE = highcharts-export-server.log
HIGHCHARTS_LOG_DEST = log/

# UI config
HIGHCHARTS_UI_ENABLE = true
HIGHCHARTS_UI_ROUTE = /

# Other config
HIGHCHARTS_NO_LOGO = false

# Proxy config
PROXY_SERVER_HOST =
PROXY_SERVER_PORT =
PROXY_SERVER_TIMEOUT =

const Hapi = require('@hapi/hapi');
const exporter = require('highcharts-export-server');
const fs = require('fs');
exporter.killPool();
const init = async () => {
  const server = Hapi.server({
    port: 3000,
    host: 'localhost',
  });

  server.route({
    method: 'GET',
    path: '/export-chart',
    handler: async (request, h) => {
      const exportSettings = {
        export: {
          type: 'pdf', 
          options: {
            title: {
              text: 'My Chart',
            },
            xAxis: {
              categories: ['Jan', 'Feb', 'Mar', 'Apr'],
            },
            series: [
              {
                type: 'bar',
                data: [1, 3, 2, 4],
              },
              {
                type: 'line',
                data: [5, 3, 4, 2],
              },
            ],
          },
        },
      };

      // Set the new options and merge it with the default options
      const options = exporter.setOptions(exportSettings);

      try {        
        await exporter.initPool(options);        
        exporter.startExport(exportSettings, async function (res, err) {
          if (err) {
            console.log(err);
            return h.response('Error exporting chart').code(500);
          }

          // Save the PDF file locally
          const outputFile = 'downloads/exported-chart3.pdf';
          fs.writeFileSync(outputFile, Buffer.from(res.data, 'base64'));          
          

          console.log(`PDF file saved as: ${outputFile}`);
          return h.response(`PDF file saved as: ${outputFile}`);
        });
      } catch (error) {
        console.error(error);
        return h.response('Internal Server Error').code(500);
      }
      return "File save successfully.;"
    },
  });

  await server.start();
  console.log('Server running on %s', server.info.uri);
};

process.on('unhandledRejection', (err) => {
  console.log(err);
  process.exit(1);
});

init();