Hi.
We're having some troubles with unifying user ID with segments, amplitude and other tools Suppose a user fills up our typeform somewhere in discord, and we'd like to send the user's responses to amplitude, what should we set as User ID into segment/amplitude? Since this is a user who leaves the email as the only identifier, what should we set as User ID in segment/amplitude? How should we unify users in segment/amplitude, if one engages with other 3ed party tools and only leaves the email as the identifier?