Chatify Pusher ($auth_key) must be of type string

I'm using phpmaker2026 in a WAMP environment, php 8.2.31
I've created a Pusher account and enabled client events.
I've configured the Chatify extension as specified in docs. (I left the route as blank, but the software defaults to /chat).
Profile is enabled.
/chatify/storage didn't exist after generation so I've created it with Full access.

I'm able to successfully Enable/Disable Chat for a User, but the chat window displays an error:
Pusher\Pusher::__construct(): Argument #1 ($auth_key) must be of type string, null given, called in C:\wamp64\www\DEV\fixturecardchat\var\cache\dev\ContainerEo62Onu\getPusherService.php on line 24

The html for the iframe is generated as follows:

The event listener (in userfn.php) appears to be correct:

AddListener(ConfigurationEvent::class, function (ConfigurationEvent $event) {
$event->set('CHAT_URL', '/chat');
$storages = $event->get('FLYSYSTEM.storages', );
$storages['chatify.storage'] = [
'adapter' => 'local',
'options' => ['directory' => '%kernel.project_dir%/storage'],
'public_url' => 'storage', // To be used by public URL generator
'public_url_generator' => DynamicPublicUrlGenerator::class,
];
$event->set('FLYSYSTEM.storages', $storages);
$locator = $event->get('SERVICE_LOCATOR', );
$locator['chatify.storage'] = 'chatify.storage';
$event->set('SERVICE_LOCATOR', $locator);
$event->append('SECRET_KEYS', 'PUSHER_APP_SECRET');
$event->import(
[
'chatify' => [
/**
* Pusher API credentials
*/
'pusher' => [
'debug' => EnvVar('APP_DEBUG', false),
'key' => EnvVar('PUSHER_APP_KEY'),
'app_id' => EnvVar('PUSHER_APP_ID'),
'options' => [
'cluster' => EnvVar('PUSHER_APP_CLUSTER', 'mt1'),
'host' => EnvVar('PUSHER_HOST') ?: 'api-'.EnvVar('PUSHER_APP_CLUSTER', 'mt1').'.pusher.com',
'port' => EnvVar('PUSHER_PORT', 443),
'scheme' => EnvVar('PUSHER_SCHEME', 'https'),
'encrypted' => true,
'useTLS' => EnvVar('PUSHER_SCHEME', 'https') === 'https',
],

env.dev.local appears to be correct:

PUSHER_APP_ID='somevalue'
PUSHER_APP_KEY='somevalue'
PUSHER_APP_SECRET='somevalue'
PUSHER_HOST=
PUSHER_PORT=443
PUSHER_SCHEME=https
PUSHER_APP_CLUSTER='eu'

getPusherService has the following line:
$container->services['Pusher\Pusher'] = $instance = new \Pusher\Pusher(NULL, 'some value', NULL, NULL);

where 'somevalue's are the Pusher keys.

Why did /chatify/storage not exist?
Should I specify a route (to my Users table or User messages)?
why does getPusherService not have values for the other keys?

Can you help please?

I have a solution. I moved the pusher keys to env.local (See Overriding Environment Values via .env.local for details. )and now get the message interface displayed correctly.

I'm not sure why that was necessary, any ideas?

If you are using "production" environment and add your settings after previous generation, you may check env.prod.local, make sure the settings are correct, then clear the cache to make sure the new settings are properly cached by Symfony.