```js
// my-component.stories.js

import { html } from 'lit-html';

import './my-component';

export default {
  title: 'MyComponent',
};

const Template = ({ propertyA }) => html`<my-component .propertyA=${propertyA}></my-component>`;

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

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