Solved when apply tag and transport tag increases

If apply tag and transport tag increases then create standby redo logs in standby db

DGMGRL> show database verbose "PEMSAPMSstdb";

Database - PEMSAPMSstdb

  Role:            PHYSICAL STANDBY
  Intended State:  APPLY-ON
  Transport Lag:   16 hours 48 minutes 27 seconds
  Apply Lag:       16 hours 48 minutes 27 seconds
  Real Time Query: ON
  Instance(s):
    PEMSAPMSstdb


cancel the recovery first before adding

SQL> alter database recover managed standby database cancel ;

SQL> alter database add standby logfile '/backup/flash_recovery_area/TESTPMSSTDB/onlinelog/stdby_o1_mf_3_9qqbp03n_.log' size 209715200;                            
                                                                               
SQL> alter database add standby logfile '/backup/flash_recovery_area/TESTPMSSTDB/onlinelog/stdby_o1_mf_2_9qqbot0k_.log' size 209715200;                            
                                                                               
SQL> alter database add standby logfile '/backup/flash_recovery_area/TESTPMSSTDB/onlinelog/stdby_o1_mf_1_9qqbomkn_.log' size 209715200;