```js
// MyComponent.stories.js

import React from 'react';

import MyComponent from './MyComponent';

export default {
  component: MyComponent,
  title: 'A story using environment variables inside a .env file'
};

const Template = (args) => <MyComponent {...args} />;

export const Default = Template.bind({});

Default.args = {
  propertyA: process.env.STORYBOOK_DATA_KEY,
};
```