We support up to 10 custom fields in addition to the standard ones in the Mapping step. They can be used so the integration fetches different information that is already included in the SAP accounts.
It is important to emphasize that if the integration is already published and you want to make amendments to the custom fields, you will have to go to the Authorize step, revoke the access, and go through the Authorize step again, then map those fields and publish the integration.