demo.py

import json
import requests

url = 'http://192.168.2.11:8080/api/v1'
s = requests.session()

s.post(f"url/login", data={'username': 'YOUR_USERNAME', 'password': 'YOUR_PASSWORD'})

query = json.dumps([
    {
        '$unwind': {
            'path': '$work_order_items', 
            'preserveNullAndEmptyArrays': False
        }
    }, {
        '$match': {
            'work_order_items.sub_work_order_num': 'YOUR_SEARCH_SUB_WORK_ORDER_NUM'
        }
    }
]}

r = s.get(f"url/get_items_pipeline?collection=work_orders&query={query}").json()