Django: Calling images in gallery using database?

I am calling images from a model in database in django like this:

And then I want to call any one of the images that will be clicked into a modal(which I outside the for loop) which the js file with collect the image URL and pass it to the main class:

Hello!

But when the code runs, the image class "fs-gal-main" comes up with an unknown source. What do I do?