basic-authorization

from sp_api.base import Marketplaces
from sp_api.api import Catalog



credentials = dict(
    refresh_token='refresh token',
    lwa_app_id='client identifier',
    # From Seller Central, named CLIENT IDENTIFIER on website.
    lwa_client_secret='client secret',
    # From Seller Central, named CLIENT SECRET on website.
    aws_access_key='aws access key',  # From AWS IAM Setup
    aws_secret_key='aws secrey key',  # From AWS IAM Setup
    role_arn='role arn'  # arn:aws:iam::1234567890:role/SellingPartnerAPIRole
)

res = Catalog(credentials=credentials).get_item('B083LY9SMS', MarketplaceId='ATVPDKIKX0DER')
print (res)

#if you receive an authorization error try again in a few hours