Trying get API history with python

First of all / I’m a novice on this field so please apologize me If my question is for you too simple…

I’m trying to get history of states for temperature (and boiler gas consumption if I find out how to get any data through this way).
If using /api/states - it works, but when trying /api/history/period/ I receive 404 error.
I probably construct the url in a wrong way / but without idea what is wrong.
Thank you in advance for any help.

import requests
from datetime import datetime, timedelta
from urllib.parse import urlencode

url = "http://homeassistant:8123/api/history/period/"
#I have tried also ipadress:8123/....
headers = {
    "Authorization": "Bearer MYTOKEN",
    "content-type": "application/json",

# Define parameters for the query - as entity_id I use the same as is stored in sql db.
entity_id = "sensor.boiler_energy_heating"
start_time = - timedelta(days=7)  
end_time =

start_time_str = start_time.strftime("%Y-%m-%dT%H:%M:%S%Z")
end_time_str = end_time.strftime("%Y-%m-%dT%H:%M:%S%Z")

# Define payload for the query
query_params = {
    "filter_entity_id": entity_id,
    "end_time": end_time_str
# Encode query parameters
query_string = urlencode(query_params)

# Construct final URL
final_url = f"{url}?{query_string}"

# Send GET request to fetch historical data
response = requests.get(final_url, headers=headers)

# Check if request was successful
if response.status_code == 200:
    # Parse JSON response
    history_data = response.json()
    print("Failed to fetch data. Status code:", response.status_code)

looks like you forget to pass the start time

final_url = f"{url}{start_time_str}?{query_string}"