The customer authorization (provided in the link you clicked) is out of date, and does not entitle you to use the Blended Threat service.
https://www.gov.uk/government/collections/the-sports-and-recreation-sector-from-january-2021?utm_source=2da6fdb9-9f07-46fc-88a1-6c47a5e227c8&utm_medium=email&utm_campaign=govuk-notifications&utm_content=daily