@88496099 Thanks for reaching out. The only possible way is to leverage the connection string in your application to authenticate the azure app configuration.
If your application would have deployed to an Azure service that supports Managed Identity, then you could have leveraged Managed Identity to access app configuration as documented here.
In case if you don't want to expose the connection string then you need to write your own custom service that will perform the different operation/result that your end user wants rather than returning the connecting string from your custom application.