title: How to change React js environment property file (.env) at runtime
body: <p>Currently I am developing a react application. I have created a .env file and am using the environment variables in all other pages but am not able to see the .env file in the build folder. Is there any way to change the environment variables at run time in the build file?</p>
  
  <p>This will work when changing the hostname and port, etc. manually and then cresting the build. Is there any way to change the variables after creation of the build?</p>
  
  <p>Any help will appropriated.</p>
  
  <p>Thanks,
  Riya</p>