Elasticsearch not saving emoji

Question

How we can enable saving of emoji or emoticons in elasticsearch.

As emoji is not supported it becomes ????? instead of emoji. I am able to save the unicode characters and data from different languages but not emoji.

Eg: Emoticons 😜 becomes Emoticons ????

$params = [
    'index' => 'my_index',
    'id'    => 'my_id',
    'body'  => [ 'testField' => 'Test emoji 😜']
];

// Document will be indexed to my_index/_doc/my_id
$response = $client->index($params);