How to retain archivelogs for the db_flashback_retention_target period

Hi

Oracle 19.6

Currently, flashback retention is 24h

db_flashback_retention_target=1440

I am currently doing archivelog backups several times a day with command:

sql 'alter system archive log current';

backup archivelog all format '__external_nfs_location__' delete all input;

But the problem with this is, whenever there is a need to do flashback database, then it may not be possible since archivelogs are deleted from ASM disks.

Ofcourse I could just remove this "delete all input"

But this means whenever I do next archivelog backup, then the next archivelog backup contains duplicate archivelogs.

Meaning:

1. doing archivelog backup on time X, there will be archive log sequences "500-550"