See the MajorApi: QuickBooks REST API for more information on how to use the MajorApi: QuickBooks REST API.
Setup
```python
from majorapi import MajorApiQuickbooks
api = MajorApiQuickbooks('username', 'apikey')
```
Customers
```python
api.create_customer(customer)
api.retrieve_customer(customer_name)
```
Orders
```python
api.create_invoice(order)
api.create_sales_order(order)
api.retrieve_invoice(ref_number)
api.retrieve_sales_order(ref_number)
```
Items
```python
api.retrieve_item(item_name)
```