title: How can I get JSON data from a browser extension (Chrome) from another server?
body: <p>I am writing a browser extension that should periodically receive the exchange rate in the JSON format and place it in local storage.
  But when I try to do this in the code of a page of any site, I get error:</p>
  <pre><code>Access to XMLHttpRequest at 'https://my.server.domain/currency.txt' from origin 'https://developer.mozilla.org' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.
  </code></pre>
  <p>Sample request code</p>
  <pre><code>$updateUrl = &quot;hhttps://my.server.domain/currency.txt&quot;;
  $.get($updateUrl).done(function($updData) {
  
  });
  </code></pre>
  <p>The only place where I can run a script like this is in <strong>popup.html</strong>, but I need updates to be triggered automatically.
  I tried to do it through Background but in <strong>manifest v3</strong> there is no such possibility anymore.</p>
  <p>The only option is to periodically open the update.html extension page and perform updates in it, but this happens by opening a new tab, and I would like to do this in the background.</p>
  <p>Any tips?</p>