Stuck on verticle tabs

Hi, I copied the vertical tab code from w3schools and I panned through the javascript and html code and it should be working. anyone have any ideas what this could be ? if you need me to copy paste the code, it’s just the same as here:

There’s not much I can do without seeing your actual code. Could you upload your project on codepen or jsfiddle and link it here? My guess, since you say you simply copied the code, is that you forgot to copy either the html, CSS, or JavaScript code (there are three steps in that link you provided so its three things you had to copy).