get https://www.virustotal.com/api/v3/monitor_partner/files//download_url
This endpoint allows you to get a download url for a file with a given sha256 hash. These URLs are ephemeral and have a one hour expiration date.
import requests
session = requests.Session()
session.headers = {'X-Apikey': '<api-key>'}
url = "https://www.virustotal.com/api/v3/monitor_partner/files/{sha256}/download_url"
response = session.get(url)
print(response.text)