try this way:
import os

import xmlrpc.client

url = os.getenv('url')

db = os.getenv('db')

username = os.getenv('user')

password = os.getenv('password')

common = xmlrpc.client.ServerProxy('{}/xmlrpc/2/common'.format(url))

uid = common.authenticate(db, username, password, {})

models = xmlrpc.client.ServerProxy('{}/xmlrpc/2/object'.format(url))

# Search for sale orders

sale_orders = models.execute_kw(db, uid, password, 'sale.order', 'search', [[]])

# Read data for the first sale order

if sale_orders:

order_data = models.execute_kw(db, uid, password, 'sale.order', 'read', [sale_orders[0]])

print(order_data)

else:

print("No sale orders found.")

Hi,
1- Make certain that the Odoo API version being employed is the appropriate one, specifically XML-RPC version 2, which corresponds to Odoo 14.
2- Please verify that the URL is accurately directed to the correct Odoo server and that the database name is correct.
3- Ensure that the 'username' and 'password' variables contain the accurate login credentials for the specific Odoo user intended to access the API.
4- Ensure that the 'common.authenticate' function is functioning correctly and providing a valid 'uid,' which is essential for making subsequent API calls.
5- Verify whether all the essential Python dependencies and libraries required for making XML-RPC requests have been installed.
6- Check API Call: Review the 'models.execute_kw' call and ensure that all the parameters are correct. The format should be 'models.execute_kw(db, uid, password, model, method, args, kwargs)'.
7- Exception Handling, you can add exception handling to your code to catch any errors that may occur during the API calls.

eg:-

try:
    uid = common.authenticate(db, username, password, {})
except Exception as e:
    print("Authentication Error occurred:", e)

Hope it helps