The function is entered only when a Sage X3 user is associated with the sales rep record. This function corresponds to the value of the AUSCRMA - Function parameter (CRM chapter, COL group) of the user associated with the sales rep record. The right-click option "User information" is available in the field containing the identification code of the sales rep.
The setup used to indicate that the sales rep is a Sage X3 user is provided at the level of the field help "X3 Users".