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

backend/utils/database.js

@@ -0,0 +1,11 @@
+const mysql = require("mysql2");
+
+//Create a pool of connection to allow multiple query happen at the same time
+const pool = mysql.createPool({
+  host: "localhost",
+  user: "root",
+  database: "marketplace",
+  password: "12345678",
+});
+
+module.exports = pool.promise();