Update code

app/api/auth/[...nextauth]/route.ts

@@ -0,0 +1,25 @@
+import NextAuth, { NextAuthOptions } from 'next-auth';
+import DiscordProvider from 'next-auth/providers/discord';
+
+export const authOptions: NextAuthOptions = {
+  providers: [
+    DiscordProvider({
+      clientId: process.env.DISCORD_CLIENT_ID!,
+      clientSecret: process.env.DISCORD_CLIENT_SECRET!,
+    }),
+  ],
+  callbacks: {
+  async session({ session, token }) {
+    if (session.user && token.sub) {
+      session.user.id = token.sub;
+    } else {
+      session.user.id = '';
+    }
+    return session;
+  },
+}
+};
+
+const handler = NextAuth(authOptions);
+
+export { handler as GET, handler as POST };