Hi Jessica -- Do you have a screenshot of an example of what you are looking to do? From your description above, it seems you're looking to show the images in a web map pop-up and then add that web map to a story map.
For help with configuring Survey123 images in a web map, I think someone in the Survey123 for ArcGIS space would be better equipped to help with that.
Once you get that map configured how you want, you can just add it to your story by clicking the green , selecting Map, then finding your map under My maps.
Owen Evans
Lead Product Engineer | StoryMaps