What is the usage of the php client of elasticsearch?

This is the document, www.elastic.coguideenelasticsearchclientphp-apicurrent_quickstart.html. question: Add: Thank you! @ lyt8384. I cannot figure it out. could you tell me whether the main user can help demonstrate the following example: what to implement...

This is a document,
Https://www.elastic.co/guide/en/elasticsearch/client/php-api/current/_quickstart.html
The problem is:

Supplement:

Thank you! @ lyt8384. I cannot figure it out. could you tell me the following example:

To achieve this, enter keywords in the search box in the view and search for results. The main problem is that you do not know how to write the controller.

Note: the packages on github seem to have not been updated for a long time. I don't know how elasticsearch supports the latest version, so I want to directly use the official php client.

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