Not sure how to get weather icons to appear

I’m working on a Weather App where once you input a new city, the app updates showing the weather and an icon representing the weather. However, I downloaded the JSON file from the API with all the icons, but I am not sure how to call it or update in the app. Here is a link the Git repository: (https://github.com/jscruggsce/Weather-App)

Unsure how to reference JSON file