Hi there! Thanks for getting in touch!
Great question! While we don’t have this particular feature built in right out of the box, we offer support for this and similar modifications through template file customizations! Our Themer’s Guide has more info and includes a comprehensive list of all template files used by our plugins, so you can simply grab the appropriate files and get going. Depending on your needs, you might even consider adding a third-party plugin like Advanced Custom Fields to allow for file uploads on the WordPress backend. There are plenty of options available if you’re willing to play around a bit–I encourage you to download our free The Events Calendar plugin and give it a try! 🙂
I hope that helps to answer your question! Please don’t hesitate to follow up if there’s anything else we can do to assist!