SOLVED-Exclude directory in linux

Hi,
I’m a new user and I would like to apologize if this question is too basic.
I have searched the forum before posting but haven find a solution that i can understand.
I have found a way to add directories to be backup e,g /dbbackup but want to exclude a subfolder on that folder e.g /dbbackup/pgdump/
How do i exclude the subfolder?
I’m using
urbackupclientctl add-backupdir -n wal_archive /dbackup to add folder but havent found any way to do file exclude.
Thanks in advanced for any help.

Configuration file is on /usr/local/var/urbackup/data/settings.cfg

under

exclude_files_def=