inside the directory (cd /var/backups/fusionpbx/postgresql/) you can rm <filename>. In a very cautious note, you can use rm * in that directory. But a cleaner way would rm fusionpbx_pgsql_2023_08* removes everything from august. etc.
***edit*** you can also setup a script to remove them, but same with you, was wondering how to turn them off if possible, I didn't have these before I migrated an old instance to a new one. Not seen a cron.daily task so I'm not sure where the daily backup is coming from. Probably a setting starring me in the face so if I find it I'll report back but otherwise I'm still looking.
