Update

app/Providers/HorizonServiceProvider.php

@@ -0,0 +1,36 @@
+<?php
+
+namespace App\Providers;
+
+use Illuminate\Support\Facades\Gate;
+use Laravel\Horizon\Horizon;
+use Laravel\Horizon\HorizonApplicationServiceProvider;
+
+class HorizonServiceProvider extends HorizonApplicationServiceProvider
+{
+    /**
+     * Bootstrap any application services.
+     */
+    public function boot(): void
+    {
+        parent::boot();
+
+        // Horizon::routeSmsNotificationsTo('15556667777');
+        // Horizon::routeMailNotificationsTo('example@example.com');
+        // Horizon::routeSlackNotificationsTo('slack-webhook-url', '#channel');
+    }
+
+    /**
+     * Register the Horizon gate.
+     *
+     * This gate determines who can access Horizon in non-local environments.
+     */
+    protected function gate(): void
+    {
+        Gate::define('viewHorizon', function ($user = null) {
+            return in_array(optional($user)->email, [
+                //
+            ]);
+        });
+    }
+}