use Http\Client\Common\PluginClient;
use JWilsson\AutoRefreshOAuth2TokenPlugin;

$autoRefreshOAuth2TokenPlugin = new AutoRefreshOAuth2TokenPlugin(
    $token,
    $refreshTokenGrant,
    $options, // Options for the plugin, see below
    $refreshTokenOptions // Additional options to pass to RefreshToken::requestAccessToken()
);

$pluginClient = new PluginClient(
    $myHttpClient,
    [$autoRefreshOAuth2TokenPlugin]
);

$response = $pluginClient->sendRequest($myRequest);

// Remember to grab the token object after each call, it might have been updated with new information
$refreshedToken = $autoRefreshOAuth2TokenPlugin->getToken();