The triggers and functions feature of Redis Stack and its documentation are currently in preview, and only available in Redis Stack 7.2 or later. You can try out the triggers and functions preview with a free Redis Cloud account. The preview is available in the fixed subscription plan for the Google Cloud Asia Pacific (Tokyo) and AWS Asia Pacific (Singapore) regions.
If you notice any errors in this documentation, feel free to submit an issue to GitHub using the "Create new issue" link in the top right-hand corner of this page.