open_basedir in linux plesk error

I am trying to load a script from another webspace in plesk. I enabled open_basedir in the webspace and in my script I insert

include "/var/www/vhosts/example.com/httpdocs/app/";

However this is not working and I receive the following errors in log:

mod_fcgid: stderr: PHP Warning: include(/var/www/vhosts/example.com/httpdocs/eshop): failed to open stream: No such file or directory in /var/www/vhosts/test.example.com/httpdocs/index.php on line 2



mod_fcgid: stderr: PHP Warning: include(/var/www/vhosts/example.com/httpdocs/app): failed to open stream: No such device in /var/www/vhosts/test.example.com/httpdocs/index.php on line 2





mod_fcgid: stderr: PHP Warning: include(): Failed opening '/var/www/vhosts/example.com/httpdocs/app/' for inclusion (include_path='.:/usr/share/php:/usr/share/pear') in /var/www/vhosts/test.example.com/httpdocs/index.php on line 2

I assume that it has to do with the fact that I am writing the path in a wrong way but I cant understand what is the correct one.