[SOLVED] How can I call a Google Application using CI4

I have developed a couple of PHP online websites using Google Books API and struggling to get the API to work with CI4.

With PHP I use Composer to download the API then the following couple of lines and it works a treat:

Code:

require_once '/var/www/ci2/vendor/autoload.php';

$tmpUrl = 'https://console.cloud.google.com/home/dashboard?project=PROJECT_NO_GOES_HERE;

$GOOGLE_API_PROJECT_ID = 'API-KEY-GOES-HERE';

 // CI4 ==> "Class "App\Controllers\Google_Client" not found"
 $client = new Google_Client();