Hi @dan@u4eastudios.com
You can create a 2nd field group containing a text field (for the url) and attach this to all media items.
Then, when you are selecting / editing the images in the gallery field, you will see the new url field.
Then in your code, use the image ID to load in the url field – please see the docs in regards to loading data from an image.
Cheers
E
