In order to attract visitors and sales for your event, participants need to be notified where to go to view the photos and place their orders.
Early launch - before the date
For optimal results, an event can be launched early to attract more visitors. See Bring early visitors back with event followers for more information
Late launch - once photos have been uploaded
Note that events are "closed" for ordering by default, so once all the images are ready, be sure to make the event open for ordering before you share it with everyone.
Regardless of the type of launch you are doing, you'll use the same "public link". Each event has it's own unique address that can be shared on various different channels including email, SMS, Facebook, WhatsApp, etc.
By clicking the public link, visitors will be taken directly to that event and can either register (if the event is closed) or browse through the available images and place their order online.