ExpressConnect for HANA DB (ECH) uses the HANA ODBC driver to communicate with a HANA database. However, Replication Server does not include the required HANA ODBC driver. After you have installed Replication Server, download these libraries from the SAP Service Marketplace and install them.
See the Replication Server Release Bulletin > Special Installation Instructions > Installing ODBC Libraries for ExpressConnect for HANA DB.