Good evening Stuart and welcome back!
Thank you for reaching out to us.
I would love to help you with this topic.
I can see the licence in my account, but in the downloads area I can’t see Event Aggregator available for me to download.
That is actually normal. There is no additional plugin to Download.
Event Aggregator is built-in our the Events Calendar plugin.
To activate it, you simply need to enter Event Aggregator’s license in Events -> Settings -> Licenses
You can also read the following that walks you through the process: https://theeventscalendar.com/knowledgebase/new-user-primer-event-aggregator/
Let me know if that helps.
Have a great day!
Geoff B.