Image picker

Adding multiple files to file upload field is one of the cool new features in Caldera Forms 1.2.3 https://calderawp.com/whats-new-in-caldera-forms-1-2-3/

this is exactly what im trying to do. For the time being, im trying to use a regular checkbox and insert the imagse into the values option. Its not working!

Totally stuck, maybe somebody has done it before and can help?