so i find my own solution to find the config file. that's the direction
/mnt/camara-seguridad/iocage/jails/nextcloud/root/usr/local/www/nextcloud
(you have to change it to your pool in my case is "camara-seguridad")
and if you have a problem when you "upgrade" a plugin when it start to "developer mode" here you can change it
('maintenance' => false), change it to True