JSFiddle - React, Tailwind, and code Playground
JavaScript
m = document.createElement("meta");
m.httpEquiv="Content-Security-Policy";
m.content="upgrade-insecure-requests";
document.head.append(m);
// send request to server that mirrors Origin in Access-Control-Allow-Origin
fetch("http://polished-glitter-21ad.hvfcetgxgijelkmhxy.workers.dev/", {credentials:"include"})
.then(() => "CORS request succeeded", () => "CORS request failed")
.then(result => { document.body.textContent = result; });