自定义字体形状怎么用js敲

@font-face {
    font-family: 'MyCustomFont';
    src: url('mycustomfont.eot'); /* IE9 Compat Modes */
    src: url('mycustomfont.eot?#iefix') format('embedded-opentype'), /* IE6-IE8 */
         url('mycustomfont.woff2') format('woff2'), /* Super Modern Browsers */
         url('mycustomfont.woff') format('woff'), /* Modern Browsers */
         url('mycustomfont.ttf') format('truetype'), /* Safari, Android, iOS */
         url('mycustomfont.svg#mycustomfont') format('svg'); /* Legacy iOS */
}

body {
    font-family: 'MyCustomFont', sans-serif;
}

function loadFont(url, fontFamily) {
    return fetch(url)
        .then(response => response.arrayBuffer())
        .then(bytes => {
            const font = new FontFace(fontFamily, bytes);
            return font.load();
        })
        .then(loadedFont => {
            document.fonts.add(loadedFont);
            return loadedFont;
        });
}

loadFont('path/to/mycustomfont.woff2', 'MyCustomFont')
    .then(() => {
        console.log('Font loaded successfully!');
        document.body.style.fontFamily = 'MyCustomFont, sans-serif';
    })
    .catch(err => console.error('Failed to load font:', err));