How to create connection to MongoDB?

How to create connection to MongoDB?

I can't create a connection to MongoDB, I do not know where to configure the connection.

https://docs.phalcon.io/en/latest/reference/odm.html Where do I put the code:

// Simple database connection to localhost 
$di-> set ('mongo', function () {
     $ mongo = new MongoClient ();
     return $ mongo->selectDB("store");
}, True); 

// Connecting to a domain socket, falling back to localhost connection 
$ di->set('mongo', function () {
     $ mongo = new MongoClient("mongodb:///tmp/mongodb-27017.sock,localhost:27017");
     return $ mongo->selectDB("store");
}, True); 

Could someone help?