From my React JS app , I need to fetch data from servers in other domains. However, I am prevented by CORS policy and not able to fetch the data.

Let us assume that my React app is running on localhost:3000 during the development. I want to make get/post call to another server running on http://myserver.com The URL through which I want to fetch the data is http://ext-server.com/data/records?name=xyz

I have installed http-proxy-middleware thru npm and using it in my react app. Created a setupProxy.js file under src folder with below content :

const { createProxyMiddleware} = require("http-proxy-middleware")
module.exports = app => {
   app.use(
      createProxyMiddleware('/data/records' , {
        target:'http://ext-server.com',
        changeOrigin: true
     })
 )
}

On the landing page of my react app (firstpage.js) when http://localhost:3000 is hit , I have added below piece of code to the button event that makes the get call to the http://ext-server.com

getTheData() {
  
let url = "http://ext-server.com/data/records?name=" + encodeURIComponent(this.state.name); 

axios.get(url,
  { 
    headers: {
     "Content-Type":"application/json;charset=UTL-8",
     "Access-Control-Allow-Origin": "*",
     Accept: "application/json",
      }, 
      baseURL: 'http://ext-server.com'
   }
 ).then((response) => {
     console.log(response["access_token"]);
  }).catch(error) => {
       console.log("Error: ", error)
  }).then(function () {
       console.log("always call it")
});

}

In the package.json , I have added :

"proxy": "http://ext-server.com",
"homepage":"http://localhost:3000",

But I am still getting below error: Access to XMLHttpRequest at 'http://ext-server.com/data/records?name= ' from origin 'http://localhost:3000' has been blocked by CORS policy.

Is there anything that I am missing here ? what is the correct way to use this http-proxy-middleware? Any help will be very useful! Thanks