Create a user exit to connect to SAP Learn how to create a user exit in SAP so you can map more information from SAP to Tax Determination. Use ZXFYTU03 from the function module EXIT_SAPLFYTX_USER_001 to create a user exit. Change the available fields in the changing parameter with CH_USER_CHANGED_FIELDS. Note: All customizations must be performed by your organization, as Sovos does not have access to your SAP system.