repmgr requires that the database defined in the conninfo setting contains the repmgr extension. The database user defined in the conninfo setting must be able to access this database and the database objects contained within the extension.

The repmgr extension can only be installed by a superuser. If the repmgr user is a superuser, repmgr will create the extension automatically.

Alternatively, the extension can be created manually by a superuser (with "CREATE EXTENSION repmgr") before executing repmgr primary register.