Update app.js

app.js

@@ -617,7 +617,7 @@ app.post('/create-payment-link', express.json(), async (req, res) => {
 
     // Persist slug -> userId mapping so webhooks can recover missing metadata later
     try {
-      const slug = pageData.page.slug || pageData.data?.slug || null;
+      const slug = pageData.slug || pageData.data?.slug || null;
       const pageId = pageData.id || pageData.data?.id || null;
       if (slug && db) {
         await db.collection('paystack-page-mappings').doc(String(slug)).set({