Hello, I am a seller from Korea and I want to use Amazon's API. I tried to receive a list through Python, but I encountered the error 'HTTP error occurred: 400 Client Error:', and I'm having trouble calling the API. How can I resolve this issue? Below is the Python code that I am trying to use.

import requests

import pandas as pd

from datetime import datetime, timezone

client_id =

client_secret =

refresh_token =

marketplace_id = 'ATVPDKIKX0DER'

def get_access_token():

url = 'https://api.amazon.com/auth/o2/token'

payload = {

'grant_type': 'refresh_token',

'refresh_token': refresh_token,

'client_id': client_id,

'client_secret': client_secret

}

headers = {'Content-Type': 'application/x-www-form-urlencoded'}

response = requests.post(url, data=payload, headers=headers)

response.raise_for_status()

return response.json()['access_token']

def get_categories(access_token):

url = 'https://sellingpartnerapi-na.amazon.com/definitions/2020-09-01/productTypes'

headers = {

'Authorization': f'Bearer {access_token}',

'x-amz-access-token': access_token,

'x-amz-date': datetime.now(timezone.utc).strftime('%Y%m%dT%H%M%SZ'),

'x-amz-marketplace-id': marketplace_id,

'Content-Type': 'application/json'

}

response = requests.get(url, headers=headers)

response.raise_for_status()

return response.json()

def save_categories_to_excel(categories, filename):

category_list = []

for category_name, category_info in categories.get('productTypes', {}).items():

category_list.append({

'Category Name': category_name,

'Requirements': ', '.join(category_info.get('requirements', {}).get('attributes', []))

})

df = pd.DataFrame(category_list)

df.to_excel(filename, index=False)

print(f"Categories saved to {filename}")

if __name__ == '__main__':

try:

access_token = get_access_token()

categories = get_categories(access_token)

save_categories_to_excel(categories, 'amazon_categories.xlsx')

except requests.exceptions.HTTPError as err:

print(f"HTTP error occurred: {err}")

except Exception as e:

print(f"Error: {e}")

error massage : 'HTTP error occurred: 403 Client Error: for url: https://sellingpartnerapi-na.amazon.com/definitions/2020-09-01/productTypes'