ORA-16447: Redo apply was not active at the

admin

ORA-16447: Redo applywas not active at the target standby database
Cause: ALTER SYSTEM FLUSH REDO TO STANDBY failed because redoapply
is not active at the target database.
Action: Startredo apply at the standby database and reissue the ALTER SYSTEM
FLUSH REDO TO STANDBY statement, or reissue the ALTER SYSTEM FLUSH
REDO TO STANDBY statement with the NO CONFIRM APPLY clause.