panel/config/initializers/inflections.rb

ActiveSupport::Inflector.inflections(:en) do |inflect|
  inflect.plural 'invitadx', 'invitadxs'
  inflect.singular 'invitadxs', 'invitadx'
end

ActiveSupport::Inflector.inflections(:es) do |inflect|
  inflect.plural 'invitadx', 'invitadxs'
  inflect.singular 'invitadxs', 'invitadx'
end