Delete a cookie when wrong password is entered in devise

Rails
1

How do you have control (in this case deleting a cookie) after devise
has determined that a user has entered the wrong password in the
latest version of devise. I have my own custom failure app but cookies
are not accessible within it:

class CustomFailureApp < Devise::FailureApp

def respond
unless request.format.to_sym == :html
http_auth
else
store_location!
flash[:alert] = i18n_message

    if request.subdomain == 'abc' && i18n_message.includes?

(‘Invalid login or password’)
cookies.delete :tracker_for_external_clients

      uri = URI('http://abc.com/?page_id=425')
      params = { 'message' => i18n_message }
      uri.query = URI.encode_www_form(params)

      res = Net::HTTP.get_response(uri)

      if res.is_a?(Net::HTTPSuccess)
        Rails.logger.info "The response is #{res.body}"
      else
        Rails.logger.info "Something went wrong"
      end

        redirect_to redirect_url
 end

end