hass-core/homeassistant/components/mill/strings.json

{
  "config": {
    "abort": {
      "already_configured": "[%key:common::config_flow::abort::already_configured_account%]"
    },
    "error": {
      "connection_error": "[%key:common::config_flow::error::cannot_connect%]"
    },
    "step": {
      "user": {
        "data": {
          "username": "[%key:common::config_flow::data::username%]",
          "password": "[%key:common::config_flow::data::password%]"
        }
      }
    }
  }
}