How to use the fonteditor-core/ttf/font.toBase64 function in fonteditor-core

}

        if (syncConfig.eot) {
            fontType.push('eot');
            syncData.eot = font.toBase64(ttf2eot(buffer));
        }

        buffer = null;
    }

    if (syncConfig.svg) {
        fontType.push('svg');
        let svg = font.create(ttf).write({
            type: 'svg'
        });
        syncData.svg = font.toBase64(svg);
    }

    syncData.encode = 'base64';
    syncData.fontName = syncConfig.name;
    syncData.fontType = fontType.join(',');
    return syncData;
}

if (syncConfig.woff || syncConfig.ttf || syncConfig.eot) {
        ttf = resolvettf(ttf);
        try {
            buffer = font.create(ttf).write({
                type: 'ttf'
            });
        }
        catch (e) {
            program.fire('font-error', e);
            alert(e.message);
            throw e;
        }

        if (syncConfig.ttf) {
            fontType.push('ttf');
            syncData.ttf = font.toBase64(buffer);
        }

        if (syncConfig.woff) {
            fontType.push('woff');
            syncData.woff = font.toBase64(ttf2woff(buffer));
        }

        if (syncConfig.eot) {
            fontType.push('eot');
            syncData.eot = font.toBase64(ttf2eot(buffer));
        }

        buffer = null;
    }

    if (syncConfig.svg) {