How to instruct Oracle to use the flash recovery area as archive log destination

Find out what the current setting is:

sqlplus / as sysdba
SQL> show parameter db_recovery
NAME                         TYPE          VALUE
---------------------------- ------------- ------------------------
db_recovery_file_dest         string        /data/oracle/PRODDB/f01
db_recovery_file_dest_size    big integer   500G

show parameter log_archive
NAME                         TYPE             VALUE
--------------------------- -------------- --------------------------
log_archive_dest_1           string        LOCATION=/data/oracle/PRODDB/u01/newarchloc/

Then, switch to the flash recovery area:

alter system set log_archive_dest_1='location=use_db_recovery_file_dest' scope=both;