BACKUPis the key you need to configure within the SnapCenter resource configuration as "HDB Secure User Store Keys", based on your hdbuserstore configuration.
hanahost:/opt/NetApp/snapcenter/scc/etc # /usr/sap/BAT/HDB00/exe/hdbuserstore list
DATA FILE : /root/.hdb/hanahost/SSFS_HDB.DAT
KEY FILE : /root/.hdb/hanahost1/SSFS_HDB.KEY
KEY BACKUP
ENV : hanahost.hanadomain.net:30015
USER: BAT_BACKUP
The HDBSQL OS user within SnapCenter is root.