The customer authorization (provided in the link you clicked) is out of date, and does not entitle you to use the Blended Threat service.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.eventbrite.com/e/lets-go-sea-gardening-tickets-46529758761?aff=utm_source%3Deb_email%26utm_medium%3Demail%26utm_campaign%3Dnew_event_email&utm_term=eventurl_text