This server is expecting a MONGO_URI environment variable defined in a .env file at root level. You can check out the schema for User and Order collections inside the directory models. That will help you populate the db with initial data if needed.

Unsurprisingly, run

npm i
npm start

inside the root directory in order to run.

to add a new user: curl -d '{"name": "Jiggly", "surname": "Puff", "age": 100}' -H "Content-Type: application/json" -X POST http://localhost:3000/users

to try to add a new user and have it fail: curl -d '{"surname": "Chu", "age": 100}' -H "Content-Type: application/json" -X POST http://localhost:3000/users prompts errors!

to update a user: curl -d '{"name": "Jiggly", "surname": "Puff", "age": 3}' -H "Content-Type: application/json" -X PUT http://localhost:3000/users/5f4f5726ddde594d290c80d1

to add an order: curl -d '{"price": 10, "user": 2}' -H "Content-Type: application/json" -X POST http://localhost:3000/orders

to update an order curl -d '{"price": 12, "user": 5}' -H "Content-Type: application/json" -X PUT http://localhost:3000/orders/5

to delete a user: curl -X DELETE http://localhost:3000/users/5f4d7587bf290843cc1e7f95