Hello Charlotte,

Thank you for reaching out! To change the reminder notification to 3 weeks before the event, you can follow these steps:

1. Go to the Amelia plugin settings in your WordPress dashboard.
2. Navigate to Notifications.
3. Create a new notification for the event.
4. Set the notification to be sent out 3 weeks before the event by adjusting the time under the notification settings.

This will ensure that the reminder is sent at your desired time.

Let me know if you need any further assistance!