Using ebextensions to run commands while deploying the app in dev uat prod

Question

Hey,

We earlier had a plaintext credentials in our Web.config/web.dev.config/web.uat.config/web.prod.config.
For security reasons we encrypted our config files using webfarms aspnet_regiis.exe.
And i was able to export the RSA key and in other machine i am able to import that rsa key and able to run the application locally using encrypted web.config.

Well when it comes to the Dev/UAT/Prod i am still blocked to use the respected encrypted configs.

can some one help me out in creating .ebextensions folder with respective env.config with required commands to execute while deplyoing app in the respective environment.
I have seen many examples people using option_settings, commands, container_commands can any body help me this. Any help can be appreciated!