Maybe I’m doing something wrong, but, when I want to add symbols from Material Design, somes of then are not working.

For exemple, karate is not working but lamp works
https://materialdesignicons.com/icon/karate
https://materialdesignicons.com/icon/lamp

{
            name: "calendar1",
            styleName: "style_custom1",
            symbol: 'karate@md',
            oneLineEvent: 1,
            url: "...",
          },
	  {
	    name: "calendar2",
            styleName: "style_custom1",
            symbol: 'lamp@md',
            oneLineEvent: 1,
            url: "...",
          },

Any idea?