If you are struggling to connect to the DB

[suzydev]

If youre struggling to connect to the DB and get this error on the terminal MongooseServerSelectionError: connect ECONNREFUSED ::1:27017

Change your connection string to -mongodb://0.0.0.0:27017/

[halfway-there1]

For local MongoDB databases, we recommend using 127.0.0.1 instead of localhost. This is because Node.js 18 and up prefer IPv6 addresses, which means that, on many machines, Node.js will resolve localhost to the IPv6 address ::1, and Mongoose will be unable to connect unless the MongoDB instance is running with IPv6 enabled.

Source: Mongoose Documentation