In order to update the selfies for multiple guests in one single operation, you can upload a ZIP file containing multiple selfie images at the following location:
Each image file should be named with the barcode of the guest that it should be applied to.
Supported image formats
Currently, PNGs and JPEGs are supported.
Recommended image resolution
The recommended resolution is 1024 by 1024 pixels.
If you can't ensure the recommended resolution, at least make sure that the aspect ratio the uploaded images is 1:1.
Determining the barcode numbers of your guests
You can go to your event in Boomset, then go to your event's Analyze page, and click the "Download Reports" button. A few moments later, you should receive a full report in your email, from where you can retrieve the barcode number of each of your guests.