HiĀ Francesco!
Thanks for reaching out to us! That’s a really nice website š
First, please let me note that we are fairly limited in how much support we can give for custom development questions like that. That said, we always like helping out and at least point users into the right direction as much possible.
By default, The Events Calendar supports featured images for events.
If you need to add multiple images for an event, then I’d suggest you take a look at the following thread where there are some suggestions on how to do it >Ā https://theeventscalendar.com/support/forums/topic/add-multiple-images-for-event/
Additionally, let me point you to our themer’s guide that shows a few methods you can use to customize our templates >Ā https://theeventscalendar.com/knowledgebase/themers-guide/
I hope that helps. Let me know if any follow up questions.
Best,
Victor