适用于PHP和Codeigniter的Google API客户端库3

Could someone explain how in install the Google APIs Client Library in Codeigniter 3 please? I am not using composer.

I have downloaded a zip file (google-api-php-client-2.1.1), but I'm unsure where to unzip it and include it in Codeigniter.

The documentation states;

Uncompress the zip file you download, and include the autoloader in your project:

require_once '/path/to/google-api-php-client/vendor/autoload.php';

I do this in application/vendor/google/google-api-php-client/vendor and require like

require APPPATH . 'vendor/google/google-api-php-client/vendor/autoload.php';

edit: require it in your controller where you need it (or model, depends on your setup)