[1] https://decoder.bip70.org/
[2] https://alexk111.github.io/DeBitpay/
Or you can do that yourself:
curl -X GET https://bitpay.com/i/$BITPAYINVOICEID -H 'accept: application/payment-request'
Equivalent Python
from requests import get
url = 'https://bitpay.com/i/BITPAYINVOICEID'
resp = get(url, headers={'Accept' : 'application/payment-request'}).json()
print(resp)
The first one is also described in the same URL you linked above. Just use python or do a GET request with the "Accept: ..." header to the URL of the invoice and the response will be all the data you need.