How to change a SAMBA user password from Node JS?

Question

I'm trying to change a LDAP password from Node JS using LDAPJS. The LDAP server is embedded in our SAMBA server.

       client.bind("CN=<myadministratorchain>", "<administratorpassword>", function(err) {
        if(err) {
            return done(err);
        }
        var change = new ldap.Change({
            operation: "replace",
            modification: {
                userPassword : "mynewpassword",
            }
        });



        client.modify("<theuserDN>", change, function(err) {
            done(err);
        });
    });

Bind and modify are both OK. I can see a new property userPassword in my SAMBA user manager but my password isn't changed when I try to connect with my those credentials.

I've tried to use exop function but it doesn't work as well.

Is there a way to change a SAMBA user's password from Node JS ?

Thanks for your help.