storybook/docs/_snippets/main-config-manager-head.md

export default {
  // Replace your-framework with the framework you are using (e.g., react-webpack5, vue3-vite)
  framework: '@storybook/your-framework',
  stories: ['../src/**/*.mdx', '../src/**/*.stories.@(js|jsx|mjs|ts|tsx)'],
  managerHead: (head) => `
    ${head}
    <link rel="preload" href="/fonts/my-custom-manager-font.woff2" />
  `,
};

// Replace your-framework with the framework you are using (e.g., react-webpack5, vue3-vite)
import type { StorybookConfig } from '@storybook/your-framework';

const config: StorybookConfig = {
  framework: '@storybook/your-framework',
  stories: ['../src/**/*.mdx', '../src/**/*.stories.@(js|jsx|mjs|ts|tsx)'],
  managerHead: (head) => `
    ${head}
    <link rel="preload" href="/fonts/my-custom-manager-font.woff2" />
  `,
};

export default config;