Can email server settings be made configurable for easy modification?

I tried it, but it didn’t work.

  #DISCOURSE_SMTP_ADDRESS: smtp.mailgun.org
  #DISCOURSE_SMTP_USER_NAME: forums@xxx.com
  #DISCOURSE_SMTP_PASSWORD: xxx
  #DISCOURSE_SMTP_PORT: 587
  #DISCOURSE_NOTIFICATION_EMAIL: noreply@xxx.com
  #DISCOURSE_SMTP_DOMAIN: forums.xxx.com

After commenting out the configuration above, the admin panel displays the following:


I don’t see anywhere that can be filled in automatically.