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

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

import MyComponent from './my-component.component';

<Meta title='A MDX story using environment variables inside a .env file' component={MyComponent}/>

export const Template = (args) => ({ props: 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>
```