title: Single-SPA localhost CROS origin Issue- React Application
body: <p>I'm new to react..I have react application which i migrated to Single-SPA.
  To integrate my application with the master application(platform which has many Vue single-spa applications) i have re-structured as </p>
  
  <p><strong>MainApp</strong> - It includes all the pages related to process - running under localhost:3000 </p>
  
  <p><strong>root-html-file</strong> - it includes one index.html and package.json file
  index.html (running under localhost:5000- generate by SPA)</p>
  
  <p>code:
  root-html-file -> index.html</p>
  
  <pre><code>&lt;script type="systemjs-importmap"&gt;
        {
          "imports": {
      "myapp": "http://localhost:3000/",
      "single-spa": "https://cdnjs.cloudflare.com/ajax/libs/single-spa/4.3.7/system/single-spa.min.js",
      "react": "https://cdnjs.cloudflare.com/ajax/libs/react/16.8.6/umd/react.development.js"
       }}&lt;/script&gt;
  
  Promise.all([System.import('single-spa'),System.import('react')]).then(function (modules) {
            var singleSpa = modules[0];
              singleSpa.registerApplication(
                  'myapp',
                  () =&gt; System.import('myapp'),
                  location =&gt; true
              );
            singleSpa.start();
  </code></pre>
  
  <p>myapp application working fine as standalone.
  Only when running root-html-file application (npm run serve) which will load myapp application into it causes CROS origin issue.Please find the screenshot
  <a href="https://i.stack.imgur.com/kGHo2.png" rel="noreferrer">enter image description here</a></p>
  
  <p>Please guide me if i'm wrong direction.</p>