storybook/docs/_snippets/args-in-preview.md

export default {
  // The default value of the theme arg for all stories
  args: { theme: 'light' },
};

// Replace your-renderer with the renderer you are using (e.g., react, vue3, angular, etc.)
import { Preview } from '@storybook/your-renderer';

const preview = {
  // The default value of the theme arg for all stories
  args: { theme: 'light' },
} satisfies Preview;

export default preview;

// Replace your-renderer with the renderer you are using (e.g., react, vue3, angular, etc.)
import { Preview } from '@storybook/your-renderer';

const preview: Preview = {
  // The default value of the theme arg for all stories
  args: { theme: 'light' },
};

export default preview;