add sitemap by code

app/sitemap.ts

@@ -0,0 +1,24 @@
+import type { MetadataRoute } from 'next'
+ 
+export default function sitemap(): MetadataRoute.Sitemap {
+  return [
+    {
+      url: 'https://oneandallmusic.net/',
+      lastModified: new Date(),
+      changeFrequency: 'yearly',
+      priority: 1,
+    },
+    {
+      url: 'https://oneandallmusic.net/aboutus',
+      lastModified: new Date(),
+      changeFrequency: 'monthly',
+      priority: 0.8,
+    },
+    {
+      url: 'https://oneandallmusic.net/electronicorgan',
+      lastModified: new Date(),
+      changeFrequency: 'weekly',
+      priority: 0.8,
+    },
+  ]
+}