I want to set up User ID in GA using GTM, by getting a UID via the cookie. The problem is that we store only the account email address in the cookie, and we don't store any unique UID. We can't send this email address to GA since sending personally identifiable information (PII) is not allowed.
A UID is stored on the back-end, but it would take development effort to retrieve it and store it in the cookie. That's a no bueno because I really need this implemented as soon as possible without involving developers.