The customer authorization (provided in the link you clicked) is out of date, and does not entitle you to use the Blended Threat service.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/guidance/student-finance-arrangements-in-a-no-deal-scenario?utm_source=642e18ad-8243-44ca-988a-2485e65383ba&utm_medium=email&utm_campaign=govuk-notifications&utm_content=immediate