```ruby
class ApplicationController < ActionController::Base
  # Prevent CSRF attacks by raising an exception.
  # For APIs, you may want to use :null_session instead.
  protect_from_forgery with: :exception
end
```

Allow username to be noted down in the signup form
user
```ruby
class ApplicationController < ActionController::Base
  before_action :configure_permitted_parameters, if: :devise_controller?
	# Prevent CSRF attacks by raising an exception.
	# For APIs, you may want to use :null_session instead.
	protect_from_forgery with: :exception
	protected

	def configure_permitted_parameters
		devise_parameter_sanitizer.for(:sign_up) { |u| u.permit(:username, :email, :password, :password_confirmation) }
		devise_parameter_sanitizer.for(:sign_in) { |u| u.permit(:login, :username, :email, :password) }
		devise_parameter_sanitizer.for(:account_update) { |u| u.permit(:username, :email, :password, :password_confirmation, :current_password) }
	end
end
```
assistant