1. DeprecationWarning: `open()` is deprecated in mongoose >= 4.11.0, use `openUri()` instead, or set the `useMongoClient` option if using `connect()` or `createConnection()`. See http://mongoosejs.com/docs/4.x/docs/connections.html#use-mongo-client Mongoose Connecting to MongoDB v4.13.20 Connections You can connect to MongoDB with the mongoose.connect() method. mongoose.connect('mongodb://localh..