how to generate the .env file ruby on rails code example

Example 1: rails call env file

#in the .ENV file:
SECRET_TOKEN=qoLsDGcc8YEdeFQ8xWbtiwafMJvjUXpH

#in your code

key = ENV['SECRET_TOKEN']

Example 2: ruby on rails set environment variables example

MAIL_USERNAME: 'Your_Username' MAIL_PASSWORD: 'Your_Username'