Dealing with ReadableStream response from API cat-facts

I was doing a pretty easy task of getting information from an API but then i got the response as ReadableStream and things start to turn dark as always. I am trying to use the cat-facts API.

URL : https://alexwohlbruck.github.io/cat-facts/docs/

and render the results with VueJS. What i found on the internet but this code just return some random numbers.

Here is the code:

created() {
  this.getFacts();
},

methods: {
    getFacts() {
      let vm = this;

      fetch('http://localhost:8080/facts')
          .then(response => {

            const reader = response.body.getReader();
            return new ReadableStream({
              start(controller) {
                return pump();
                function pump() {
                  return reader.read().then(({ done, value }) => {
                    // When no more data needs to be consumed, close the stream
                    if (done) {
                        controller.close();
                        return;
                    }
                    // Enqueue the next data chunk into our target stream
                    vm.facts = value;
                    controller.enqueue(value);
                    return pump();
                  });
                }
              }  
            })
          })
          .catch(err => console.error(err));
  },
 }

I am using vue.config.js to manage cors error:

module.exports =  {

devServers = {
    proxy: 'https://cat-fact.herokuapp.com/'
}
}

I made the request with POSTMAN and worked just well.