discourse-chat-integration/lib/discourse_chat/provider/telegram/telegram_initializer.rb

DiscourseEvent.on(:site_setting_saved) do |sitesetting|
  isEnabledSetting = sitesetting.name == 'chat_integration_telegram_enabled'
  isAccessToken =  sitesetting.name == 'chat_integration_telegram_access_token'

  if (isEnabledSetting || isAccessToken)
    enabled = isEnabledSetting ? sitesetting.value == 't' : SiteSetting.chat_integration_telegram_enabled
    if enabled
      Scheduler::Defer.later("Setup Telegram Webhook") do
        DiscourseChat::Provider::TelegramProvider.setup_webhook()
      end
    end
  end
end