first upload all files

Modules/Coupon/Providers/CouponServiceProvider.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace Modules\Coupon\Providers;
+
+use Modules\Coupon\Admin\CouponTabs;
+use Illuminate\Support\ServiceProvider;
+use Modules\Admin\Ui\Facades\TabManager;
+
+class CouponServiceProvider extends ServiceProvider
+{
+    /**
+     * Bootstrap the application services.
+     *
+     * @return void
+     */
+    public function boot()
+    {
+        TabManager::register('coupons', CouponTabs::class);
+    }
+}