require_once('/path/to/OAuthAuthCode/vendor/autoload.php');

<?php
require_once(__DIR__ . '/vendor/autoload.php');

$apiInstance = new UPS\OAuthAuthCode\Request\DefaultApi(
    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
    // This is optional, `GuzzleHttp\Client` will be used as default.
    new GuzzleHttp\Client()
);
$client_id = "client_id_example"; // string | The public identifier for your application, obtained when you, the developer first registered the application.
$redirect_uri = "redirect_uri_example"; // string | URL that tells the authorization server where to send the user back to after they approve the request.
$response_type = "response_type_example"; // string | Valid Values: code
$state = "state_example"; // string | A random string generated by the application and included in the request to prevent CSRF attacks. The application checks that the same value is returned after the user authorizes the app.
$scope = "scope_example"; // string | One or more space-separated strings indicating which permissions the application is requesting.

try {
    $apiInstance->authorizeClient($client_id, $redirect_uri, $response_type, $state, $scope);
} catch (Exception $e) {
    echo 'Exception when calling DefaultApi->authorizeClient: ', $e->getMessage(), PHP_EOL;
}
// Configure HTTP basic authorization: basicAuth
$config = UPS\OAuthAuthCode\Configuration::getDefaultConfiguration()
    ->setUsername('YOUR_USERNAME')
    ->setPassword('YOUR_PASSWORD');

$apiInstance = new UPS\OAuthAuthCode\Request\DefaultApi(
    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
    // This is optional, `GuzzleHttp\Client` will be used as default.
    new GuzzleHttp\Client(),
    $config
);
$grant_type = "grant_type_example"; // string | 
$code = "code_example"; // string | 
$redirect_uri = "redirect_uri_example"; // string | 

try {
    $result = $apiInstance->generateToken($grant_type, $code, $redirect_uri);
    print_r($result);
} catch (Exception $e) {
    echo 'Exception when calling DefaultApi->generateToken: ', $e->getMessage(), PHP_EOL;
}
// Configure HTTP basic authorization: basicAuth
$config = UPS\OAuthAuthCode\Configuration::getDefaultConfiguration()
    ->setUsername('YOUR_USERNAME')
    ->setPassword('YOUR_PASSWORD');

$apiInstance = new UPS\OAuthAuthCode\Request\DefaultApi(
    // If you want use custom http client, pass your client which implements `GuzzleHttp\ClientInterface`.
    // This is optional, `GuzzleHttp\Client` will be used as default.
    new GuzzleHttp\Client(),
    $config
);
$grant_type = "grant_type_example"; // string | 
$refresh_token = "refresh_token_example"; // string | 

try {
    $result = $apiInstance->refreshToken($grant_type, $refresh_token);
    print_r($result);
} catch (Exception $e) {
    echo 'Exception when calling DefaultApi->refreshToken: ', $e->getMessage(), PHP_EOL;
}
?>