Fixes for listeners:

app/Listeners/Account/CreateAccountActivity.php

@@ -0,0 +1,53 @@
+<?php
+/**
+ * Invoice Ninja (https://invoiceninja.com).
+ *
+ * @link https://github.com/invoiceninja/invoiceninja source repository
+ *
+ * @copyright Copyright (c) 2021. Invoice Ninja LLC (https://invoiceninja.com)
+ *
+ * @license https://opensource.org/licenses/AAL
+ */
+
+namespace App\Listeners\Account;
+
+use App\Jobs\Mail\NinjaMailerJob;
+use App\Jobs\Mail\NinjaMailerObject;
+use App\Libraries\MultiDB;
+use App\Utils\Ninja;
+use Illuminate\Contracts\Queue\ShouldQueue;
+
+class CreateAccountActivity implements ShouldQueue
+{
+
+    /**
+     * Create the event listener.
+     *
+     * @param ActivityRepository $activity_repo
+     */
+    public function __construct()
+    {
+    }
+
+    /**
+     * Handle the event.
+     *
+     * @param  object  $event
+     * @return void
+     */
+    public function handle($event)
+    {
+        MultiDB::setDb($event->company->db);
+
+        if(Ninja::isHosted())
+        {
+            $nmo = new NinjaMailerObject;
+            $nmo->mailable = new Modules\Admin\Mail\Welcome($event->user);
+            $nmo->company =  $event->company;
+            $nmo->settings = $event->company->settings;
+            $nmo->to_user = $event->user;
+
+            NinjaMailerJob::dispatch($nmo);
+        }
+    }
+}

app/Providers/EventServiceProvider.php

@@ -11,6 +11,7 @@
 
 namespace App\Providers;
 
+use App\Events\Account\AccountCreated;
 use App\Events\Client\ClientWasArchived;
 use App\Events\Client\ClientWasCreated;
 use App\Events\Client\ClientWasDeleted;
@@ -179,6 +180,8 @@ class EventServiceProvider extends ServiceProvider
      * @var array
      */
     protected $listen = [
+        AccountCreated::class =>[
+        ],
         MessageSending::class =>[
         ],
         MessageSent::class => [