Access object property on Fastify

Question

I tried to fetch the value from the object on Fastify but while I was trying to do so, when I make GET request, it keeps loading and network request keep on pending. Here is how I tried,

I want to access the property of the object (token) and assign it to new variable, and then I tried to make GET request on browser and it is keep loading and network is pending. Here is my code written on Fastify inside the controller section.

+ Controller section

exports.getConversations = async (req, reply) => {
  try {
      var conversationId = this.authentication();
      const { token } = conversationId;
      return token;
  } catch (err) {
    throw boom.boomify(err)
  }
}

Here is the object I got from the response of this.authentication():

{
    "conversationId": "LMFeL1yqdkfjskkkd2kO5-n",
    "token": "token_value",
    "expires_in": 3600
}

Here is the routes which in inside the routes folder under the src directory:

+ Route section

const streamController = require('../controllers/streamController');
const routes = [
  {
    method: 'GET',
    url: '/api/stream/converstations',
    handler: streamController.getConversations
    // schema: documentation.schema
  },
  {
    ...
  }
]

module.exports = routes;

Can anyone help me out? Thank you in advanced.