storybook/docs/_snippets/storybook-custom-manager-head.md

export default {
  managerHead: (head) => `
    ${head}
    <link rel="icon" type="image/png" href="/logo192.png" sizes="192x192" />
  `,
};

// 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 = {
  managerHead: (head) => `
    ${head}
    <link rel="icon" type="image/png" href="/logo192.png" sizes="192x192" />
  `,
};

export default config;