created a controller

app/Http/Controllers/SignupController.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace App\Http\Controllers;
+
+use Illuminate\Http\Request;
+
+class SignupController extends Controller
+{
+    public function index()
+    {
+        return view("auth.signup");
+    }
+}

routes/web.php

@@ -1,11 +1,11 @@
 <?php
 
+use App\Http\Controllers\SignupController;
+
 use Illuminate\Support\Facades\Route;
 
 Route::get('/', function () {
     return view('main');
 });
 
-Route::get("/signup", function () {
-    return view("auth.signup");
-});
+Route::get("/signup", [SignupController::class, "index"]);