This code will show whether the user is online or offline in the top centre of the screen.
Copy and paste the body part of the index.html and paste it before or after the header tag on your page.
Copy the CSS and either paste it between the <style> tag in the same HTML or in the website style file style.css.
Make sure to eliminate body{} and other unnecessary CSS attributes to prevent code mutation.
At least copy and paste the script.js code inside your HTML code as done for CSS or paste it in a separate .js file
If you don't want to set it up on your website you can try it out in your localhost by turning ON and OFF the WiFi or Mobile Data
Last but not least mention me or my work by pasting the repo URL or my GitHub URL in your code footer with a comment tag
https://github.com/Abinbn