The customer authorization (provided in the link you clicked) is out of date, and does not entitle you to use the Blended Threat service.
http://www.acumen.hmrc.gov.uk/_/app/emailRobot/index/click/secret/1db5ab571ae085657d33929d333065cb?link=https%3A%2F%2Fwww.parliamentlive.tv%2FEvent%2FIndex%2F041436b2-2558-4b82-80a7-9fbd7d24c533