Matomo: track events

[arildm]

Current tracking only includes page views, so we'll know how users navigate between pages but not what they do on each page. With events, we can track things like button clicks and uploads. I'm not entirely sure how to best make use of this, though.

I think a first event to start tracking could be the "Run annotation" button being clicked.

See the links listed on https://matomo.org/guide/reports/event-tracking/