enable syslog

Hello,
I'm trying to use syslog in my vcl file but that doesn't work.
I can't find the /var/log/syslog file.
How can I make it works please?

    vcl 4.0;
    import std;
    sub vcl_recv {
        if (req.method != "GET" && req.method != "HEAD") {
            std.syslog(180, "BAN " + client.ip + " METHOD " +req.method);
            return (pass);
       }
    }