# .env
USERNAME="username"
DATABASE_URL="postgres://${USERNAME}@localhost/my_database"
```
```js
// index.js
console.log('DATABASE_URL', process.env.DATABASE_URL)
```
```sh
$ dotenvx run --debug -- node index.js
[dotenvx@1.X.X] injecting env (2) from .env
DATABASE_URL postgres://username@localhost/my_database
```

</details>
<details><summary>`run` - Default Values</summary><br>

Use default values when environment variables are unset or empty.

```ini