General Notes

1. WHERE IS THE README ?
2. `.env` shouldn't be on Github.
3. Why did you install `axios` and used it instead of `node-fetch?
4. Why there are empty files?
5. `test.test.js` should be called maybe `index.test.js` and should be in a separate folder on the root not in `src`.
6. There's no need to handle the `index.html` for `'/'` route, it's handled by default with `express.static`.
7. You can create a file and called it `errors` and export both `clientError` and `serverError` from it.
8. Your list of requires needs edits in order 1. core 2. 3rd party modules 3. your own modules.
9. You didn't use the `router`.
10. You should edit your file structure and split `app.js` into `index.js` which contain the initial server listening and create a controller folder and a router.
11. Why didn't you bring your `API_KEY` from the environment variables?
12. Since you know how to destructure variables, why didn't you destructure the other one?
```js
const labelValue = req.params.label;
const { option } = req.params;
```
13. Your design needs a little fixation.