Refactor code, split routes, change url in backend and update in frontend. Still have bugs, infinite loading after signup?

backend/routes/product.js

@@ -0,0 +1,10 @@
+const express = require("express");
+const { addToFavorite, getAllProducts } = require("../controllers/product");
+
+const router = express.Router();
+
+router.post("/add_fav_product", addToFavorite);
+
+router.get("/get_product", getAllProducts);
+
+module.exports = router;