By default, its not that easy to configure your application with i18n. If you wish to support your local language like esp, np, hi, mx, etc. you need to follow the steps i tell you.

Configure your routes.rb

Need to configure your routes.rb to encapsulate the controller with locale info

  # routes.rb
  scope "(:locale)", locale: /en|np/ do
    mount RailsAdmin::Engine => '/admin', as: 'rails_admin'

    devise_for :users
    root 'home#index'
    resource :dashboard do
      collection do
        get :report
      end
    end
  end

Configure locale in each request

Set the locale for each request

  # initialize/rails_admin.rb
  RailsAdmin.config do |config|

  ### Popular gems integration

  ## == Devise ==
  config.authenticate_with do
    default_locale =  :np

    # Set locale per request
    I18n.locale = params[:locale] || default_locale

    if current_user.blank? || (current_user.has_role?('super_admin') == false)
        flash[:error] = 'You are not authorized to access this resource.'
      redirect_to '/'
    end
  end

  config.current_user_method(&:current_user)

Copy yml file to your project

copy .rvm/gems/ruby-2.6.3/gems/rails_admin-1.4.2/config/locales/rails_admin.en.yml or https://raw.githubusercontent.com/sferik/rails_admin/master/config/locales/rails_admin.en.yml

to /config/locale/rails_admin.np.yml or rails_admin.[:locale].yml

Convert the file to your locale.

Common Error

You might encounter a msg in view translation missing for np.datetime.distance_in_words.x_days

add the following to the rails_admin.np.yml file

np:
  datetime:
    distance_in_words:
      x_days: "%{count} दिन"
      about_x_hours: "%{count} घण्टा"

or you can copy this file to config/locale of nepali translations.

https://gist.github.com/shivabhusal/84b4d9365bc88843c5249aa41ff57688