React js application deployment in 3 different environments

Hi , I have a React js application with 4 different environments 

1) .env -> root

2).env.test -> for Test

3).env.qa-> for QA

4).env.prod -> for Prod

But when i am deploying in test and QA environments using build and release pipeline. But when i am deploying it is taking the .env configuration instead of respect environment file.

Please guide how to deploy this kind of applications in different environments