If you are using Data Tag to store user data between the site pages, this custom variable will help to extract data that was stored by the data tag.
Check out the advantages of using GA4 and GTM server tagging and a step-by-step guide on how to send events to GA4 using the GTM server.
Learn about the new way of setting Google Tracking in web GTM using Google Tag, configuration settings, and event settings variables.
User Data Extractor for sGTM captures personal details from server-side events, such as emails and phone numbers, boosting marketing and tracking.