DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to MongoClient.connect. code example
Example: { use UnifiedTopology: true }
mongoose.connect("mongodb://localhost:27017/NAME", { useUnifiedTopology: true, useNewUrlParser: true });