Add initial Code

app/Http/Controllers/SettingController.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace App\Http\Controllers;
+
+use App\Models\Setting;
+use Illuminate\Http\Request;
+
+class SettingController extends Controller
+{
+    public function index()
+    {
+        return Setting::firstOrCreate([]);
+    }
+
+    public function update(Request $request)
+    {
+        $validatedData = $request->validate([
+            'invoice_number_format' => 'required|string',
+            'invoice_number_start' => 'required|integer',
+        ]);
+
+        $setting = Setting::firstOrCreate([]);
+        $setting->update($validatedData);
+
+        return response()->json($setting, 200);
+    }
+}