Update index.js

index.js

@@ -288,7 +288,7 @@ app.post("/api/v2/key/upgrade-key", authenticateApiKey, apiLimiter, async (req,
     );
 
     res.json({
-      apiKey: existingUser.api_keys,
+      apiKey: existingUser.key,
       createdAt: existingUser.createdAt,
       expiresAt: expirationDate,
       owner: userIdNumber,