LeanCloud CORS Headers const leancloudHeaders = require('leancloud-cors-headers'); app.options('/*', (req, res) => { res.header('Access-Control-Allow-Origin', '*'); res.header('Access-Control-Max-Age', '86400'); res.header('Access-Control-Allow-Methods', 'HEAD, GET, POST, PUT, DELETE, OPTIONS'); res.header('Access-Control-Allow-Headers', leancloudHeaders); res.end();});