I am using the field formatter to add a gallery to an image field in Drupal. I use views in drupal to show the galleries based on a taxonomy term.
I know I can us have different audio per gallery using hook_juicebox_gallery_alter() for this need.

But I have no idea how to do that or where (in which file).
Could somebody give me a hand with that?
I'm using the pro version of Juicebox v1.5.