The "Data decoding error" you're encountering with Laravel Reverb and Pusher typically indicates an issue with the data being sent or received, or a misconfiguration in your setup. Here are a few steps to troubleshoot and resolve this issue:

1. Check Your Environment Configuration: Ensure that your .env file is correctly configured and that there are no typos or incorrect values. Specifically, verify that the REVERB_HOST is correctly set to your domain.

   BROADCAST_CONNECTION=reverb
   
   REVERB_APP_ID=app_123
   REVERB_APP_KEY=key_123
   REVERB_APP_SECRET=secret_123
   REVERB_HOST="ws.{domain_name}.app"
   REVERB_SCHEME=https
   REVERB_SERVER_PORT=8080
   REVERB_PORT=443
   

2. Caddyfile Configuration: Ensure that your Caddyfile is correctly set up to handle WebSocket connections. Your configuration looks mostly correct, but double-check the reverse_proxy settings and ensure that the WebSocket headers are properly handled.

   {domain_name}.app, www.{domain_name}.app {
       root * /home/digitalocean/{domain_name}.app/current/public
       encode zstd gzip
       file_server
       php_fastcgi unix//run/php/php8.3-fpm.sock
   }
   
   ws.{domain_name}.app {
       @websockets {
           header Connection *Upgrade*
           header Upgrade websocket
       }
       reverse_proxy @websockets localhost:8080
       encode zstd gzip
   }
   
   client.{domain_name}.app {
       reverse_proxy 0.0.0.0:3000
       encode gzip
   }
   
   customer.{domain_name}.app {
       reverse_proxy 0.0.0.0:4000
       encode gzip
   }
   

3. Check SSL/TLS Configuration: Ensure that your SSL/TLS certificates are correctly set up and that there are no issues with HTTPS connections. Misconfigured SSL can sometimes cause data decoding errors.

4. Verify Reverb Server: Ensure that the Reverb server is running and accessible on the specified port (8080). You can test this by trying to connect to the WebSocket server directly using a tool like wscat:

   wscat -c ws://ws.{domain_name}.app:8080
   

5. Check for Errors in Logs: Check the logs for both your Laravel application and the Reverb server for any errors or warnings that might provide more insight into the issue.

6. Update Dependencies: Ensure that all your dependencies are up to date. Sometimes, bugs in older versions of libraries can cause unexpected issues.

   composer update
   npm update
   

7. Test with a Simple Event: Try broadcasting a simple event to see if the issue persists. This can help isolate whether the problem is with the data being sent or with the configuration.

   // In your Laravel application
   event(new \App\Events\SimpleEvent('Test message'));
   

   // SimpleEvent.php
   namespace App\Events;
   
   use Illuminate\Broadcasting\Channel;
   use Illuminate\Broadcasting\InteractsWithSockets;
   use Illuminate\Broadcasting\PresenceChannel;
   use Illuminate\Broadcasting\PrivateChannel;
   use Illuminate\Contracts\Broadcasting\ShouldBroadcast;
   use Illuminate\Foundation\Events\Dispatchable;
   use Illuminate\Queue\SerializesModels;
   
   class SimpleEvent implements ShouldBroadcast
   {
       use Dispatchable, InteractsWithSockets, SerializesModels;
   
       public $message;
   
       public function __construct($message)
       {
           $this->message = $message;
       }
   
       public function broadcastOn()
       {
           return new Channel('test-channel');
       }
   
       public function broadcastAs()
       {
           return 'simple-event';
       }
   }
   

By following these steps, you should be able to identify and resolve the "Data decoding error" you're encountering with Laravel Reverb and Pusher. If the issue persists, consider providing more detailed logs or error messages to further diagnose the problem.