$form['select_' . $key . '_callback'] = [
'#type' => 'select',
'#title' => $this->t('Test %key callbacks', ['%key' => $key]),
- '#options' => ['red' => 'red'],
+ '#options' => ['red' => 'red', 'green' => 'green'],
'#ajax' => ['callback' => $value],
];
}