Hi there.
While we don’t provide internal coding solutions for custom JavaScript, this often relates to how servers handle file paths differently than your local computer. Please ensure your script filename matches the case in your HTML exactly (e.g., script.js vs Script.js) and try a hard refresh using Ctrl + F5 to clear any cached versions of your code. You can also press F12 and check the Console tab for any red 404 errors that would indicate the server can’t find your file.