Paste this snippet into your web browser's console when viewing the Pizza Tracker page offered after submitting a Dominos order. When the state changes it'll post the order state to your specified Slack Incoming Webhook. Use the URL at the top of your existing integration to paste into the prompt you receive when running the snippet. It should be in the form of: "https://TEAM.slack.com/services/hooks/incoming-webhook?token=TOKEN".
You'll need to leave your browser window open until it's done, of course. Tested in Chrome in the UK. Not tested with collections.