Добавлены и исправлены Routes

src/App.jsx

@@ -22,10 +22,10 @@ function App() {
               <Routes>
                 <Route path="/" element={<HomePage />} />
                 <Route path="/media/:id" element={<MediaPage />} />
-                <Route path="/profile/:id" element={<ProfilePage />} />
+                <Route path="/profile/:username" element={<ProfilePage />} />
                 <Route path="/login" element={<LoginPage />} />
                 <Route path="/register" element={<RegisterPage />} />
-                <Route path="/admin/media/new" element={<AdminMediaPage />} />
+                <Route path="/admin/media" element={<AdminMediaPage />} />
                 <Route path="*" element={<NotFoundPage />} />
               </Routes>
             </main>