Built in css editor not working as expected

im trying to add text gradient from the CSS panel on weweb editor but it did not work, why is that ?

here’s my css code

  font-size: 72px;
  background: -webkit-linear-gradient(rgb(188, 12, 241), rgb(212, 4, 4));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;

i’ve read this thread Color gradient in text and border?, is this the only solution ?

Some properties don’t work in the Custom CSS input, you should try adding a custom class in custom code. You can add the class in the Settings tab of the element