Implement Zendesk chat in my own ui design

shall i use this library
https://github.com/zendesk/zendesk_api_client_php is this official?

If the answer is yes. i want to know how to handle the reply message from agent and display it in the custom ui. because it is not there.

 Right now i am using this code for chat feature:

<!-- Start of herringinfotech Zendesk Widget script --><script id="ze-snippet" src="https://static.zdassets.com/ekr/snippet.js?key=bc50e950-cfac-41a8-85e4-4ba1aedcb901"> </script><!-- End of herringinfotech Zendesk Widget script -->

This code provides zendesk's ui for chat dialog

i dont want zendesk's chat dialog . i am having my own design for chat dialog. i want to use that design along with zendesk in backend.

Please help me. how to achieve this...

Thanks