Jenkins and lavavel continuous integration project. What about the variables of env?

when doing project integration, there is a problem. The configuration of the development environment and the test environment to connect to the database is different, so when integrating, write these variables into the .env file.

I hope that every time I add a new task and add these variables to the Jenkins task, Jenkins can help me replace the corresponding values in the .env file (I have used other integration tools, which are implemented in this way).

now I can"t find where to set these variables, or do I want to install another plug-in?

,.env,:
echo "DB_HOST=>"127.0.0.1"
      DB_USER_NAME"=>YOUR USERNAME" 
     > //.env

but this is not easy to maintain, and even worse: for projects like react, their configuration goes like this:
defines these under config.js

var baseApi ="sever"

.

what I want is that variables can be configured freely, and Jenkins helps me replace the corresponding values in the configuration file.