How to add a gradient to an icon?

[grandslammer]

I have tried using a linear gradient background on the icon, which I have working for normal text. The icon just appears as black though.

background: linear-gradient(93.08deg, #f42b03 8.39%, #0076ff 91.55%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-transform: none;

I am able to make the icon a solid color just by specifying a color property in the CSS. How can I add a gradient to an icon?