Habe ich verwendet <!DOCTYPE html> <html> <head> <meta charset="utf-8" /> </head> <body> <button type="button" id="button">Click</button> <pre id="output">Not Loading...</pre> <script src="https://cdnjs.cloudflare.com/ajax/libs/babel-standalone/6.17.0/babel.min.js"></script> <script type="text/babel"> document.addEventListener('DOMContentLoaded', function () { const button = document.getElementById('button'); const output = document.getElementById('output'); output.textContent = 'Loading...';