```md
<!-- MyComponent.stories.mdx -->

import { Meta, Story, Canvas } from '@storybook/addon-docs';

import MyComponent from './MyComponent';

<Meta title="A MDX story using environment variables inside a .env file" />

export const Template = (args) => <MyOtherComponent {...args} />

<Canvas>
    <Story 
      name="A MDX story using environment variables inside a .env file" 
      args={{
        propertyA: process.env.STORYBOOK_DATA_KEY}}
      >
      {Template.bind({})}
    </Story>
</Canvas>
```