Here is the screenshot of standby : How to fix it? Thanks
SQL> alter database open read only;
alter database open read only
*
ERROR at line 1:
ORA-10458: standby database requires recovery
ORA-01196: file 1 is inconsistent due to a failed media recovery session
ORA-01110: data file 1:
'/u01/app/oracle/base/oradata/CDB/datafile/o1_mf_system_120uspna_.dbf'
ORA-16043: Redo apply has been canceled.
ORA-16016: archived log for thread 1 sequence# 97 unavailable
ORA-10877: error signaled in parallel recovery slave
ORA-10877: error signaled in parallel recovery slave