Having a cover photo for your events is a quick and effective way to capture the vibe of your event and make it stand out for potential new attendees.
You can set the photo you prefer during the event creation flow in the Featured photo section and upload a new one later if you change your mind. To edit your event's cover photo:
Open the event you'd like to edit
From ⚙️ Organizer tools, select ✏️ Edit event
If your event is repeating, choose to edit a single one or the whole series
Scroll to Featured photo and click the little ✏️ pencil icon to upload a new picture (look for it in the top-left corner of the image, as you can see in the screenshot below)
If you don't have a photo ready for use, you can always pick a free image from the Pexels photo library