How to use helm environment variables in a frontend

I'm developing a frontend which will be hosted in AKS with Helm. Now I want to make use of Helm for the environment variables, but I'm struggling with how to do it. I currently have my environment variables in a values.yaml file and I'm loading them into my deployment chart. Now Ideally these environment variables would be loaded into a json format which will be created by Helm. Does anyone know how to do this?