How to set user for cgi scripts in ispconfig?

Currently I have a perl web application. When it is trying to send email using sendmail binary it is doing it as user www-data. I would like it to be the user set by ispconfig like web123.
Here is the configuration in nginx that is working fine but I need it to be using user web123 or the respective user set by ispconfig for each web hosting.

Code:

        location ~ ^/.*\.pl$ {
                    try_files $uri =404;
                    include /etc/nginx/fastcgi_params;
                    root /var/www/clients/client1/web123/cgi-bin/perl_application;
                    gzip off;
                    fastcgi_pass  unix:/var/run/fcgiwrap.socket;
                    fastcgi_index index.pl;
                    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
                    fastcgi_intercept_errors on;
        }

Need advice on how to achieve this.

 

Yes!!!
This really helped me very much.
It is working great now!!!

Code:

sudo systemctl start fcgiwrap-web123.service

For the above command, should I also do a enable like

Code:

sudo systemctl enable fcgiwrap-web123.service

so that it will work after a reboot?