## Async/Await
See [this stackoverflow question](https://stackoverflow.com/questions/48969495/in-javascript-how-do-i-should-i-use-async-await-with-xmlhttprequest).

## PHP and JSON
In the {PHP} use
```php
$data = json_decode(file_get_contents('php://input'), true);
```
to get {JSON}, **not `$_POST` — the latter is for sending forms.