I found this method of using .env variable more suitable , fast and protective.
unlike before accessing enviroment with os package at every file and location, but here with power of using multiple ENVIROMENT file with hand in dependencies injection is much more convinent and redable.
We can use different-different .env fie at the time of initializing object and then smoothly access the varable.
Directly use config.go and look into main.go file for how to work with this.
use command make run to run file and see the value SECRET_KEY which is "secret" from .env file.