Nodejs Elastic Client Setup is not working

[Srinivas_RK]

I have setup elastic using eck guide this is working fine. i was able to run logstash by importing certificates. now im trying to write a nodejs api project to use my elastic search. trying some examples from docs

const client = new Client({
    node: 'https://mynode.eastus.cloudapp.azure.com/',
    maxRetries: 5,
    requestTimeout: 60000,
    sniffOnStart: true,
    ssl: {
        ca: fs.readFileSync('./cacert.crt'),
        rejectUnauthorized: false,
    },
    auth: {
        password: ELASTIC_PWD,
        username: ELASTIC_USER
    }
});

However it seems my ssl config is not working

const result = await client.search({
      index: 'rush_idx',
      body: {
        query: {
          match: { isbn: "243453452" }
        }
      }
    });

the above request fails with

ResponseError: security_exception
    at onBody (D:\Workspaces\RL.Elastic-API\node_modules\@elastic\elasticsearch\lib\Transport.js:333:23)
    at IncomingMessage.emit (events.js:327:22)
    at endReadableNT (_stream_readable.js:1327:12)
    at processTicksAndRejections (internal/process/task_queues.js:80:21) {
  meta: {
    body: { error: [Object], status: 401 },
    statusCode: 401,
    headers: {
      'www-authenticate': 'Basic realm="security" charset="UTF-8", Bearer realm="security", ApiKey',
      'content-type': 'application/json; charset=UTF-8',
      'content-length': '549'
    },
    meta: {
      context: null,
      request: [Object],
      name: 'elasticsearch-js',
      connection: [Object],
      attempts: 0,
      aborted: false
    }
  }
}

can anybody tell what is correct way to configure ssl certificates in this case.