Issue Roundcube and Enigma Application error 600

[psyche699]

Hello

Ok i have a plesk, on centos 7.2.

I use a multiple instance, and i need a multiple roundcube.
All mail need to crypt.

So, i have installed roundcube on :

/var/www/vhosts/mydomaine.com/httpdocs/roundcube

I installed the roundcube, with nothing error. ( with enigma )
I'm connect, and go to Settings => PGP Key.
Here have a error :

Application Error (600): Enigma plugin: GPG binary not found. If you are sure the GPG binary is installed, please specify the location of the GPG binary using the 'binary' driver option.

i think have a problem with open_basedir.
But i dont say to resolve this..

I read that : https://kb.plesk.com/en/432

The exemple is :
php_admin_value open_basedir HTTPD_VHOSTS_D/domain.com/httpsdocs:/tmp:/ADD_PATH

So, :
- HTTPD_VHOSTS_D is the path for go to my domain, right ? On centos is /var/www/vhosts right ?
- ADD_PATH is path to need a acces for open_basedir ? Right ?

Beacause my open_basedir on php.ini is :

open_basedir = "/tmp"

Is not good, right ?

Thnaks in advance.