use WebPush\VAPID\WebTokenProvider;
use WebPush\VAPID\LcobucciProvider;
$jwsProvider = WebTokenProvider::create(
'BB4W1qfBi7MF_Lnrc6i2oL-glAuKF4kevy9T0k2vyKV4qvuBrN3T6o9-7-NR3mKHwzDXzD3fe7XvIqIU1iADpGQ', // Public key
'C40jLFSa5UWxstkFvdwzT3eHONE2FIJSEsVIncSCAqU' // Private key
$jwsProvider = LcobucciProvider::create(
'BB4W1qfBi7MF_Lnrc6i2oL-glAuKF4kevy9T0k2vyKV4qvuBrN3T6o9-7-NR3mKHwzDXzD3fe7XvIqIU1iADpGQ',
'C40jLFSa5UWxstkFvdwzT3eHONE2FIJSEsVIncSCAqU'
$extensionManager = ExtensionManager::create()
->add(VAPIDExtension::create('http://my-service.com', $jwsProvider)