node js execute oracle pl sql stored function on database

exec_orafn.js

(function() {
        var db = require('oracledb');
        var plSQLFun = "begin                                " +
                       "  :ret := pkb_demo.f_get_price(:p1); " +
                       "end;                                 ";
        
        var executeOnDb = function() {
            var bindvars = {
                ret: { dir: oracledb.BIND_OUT, type: oracledb.NUMBER },
                p1:  'Y'
            };
            db.execute(
                plSQLFun,
                bindvars,
                function(err, result) {
                    if (err) {
                        console.log(err);
                    } else {

                        console.log("ret : " + result.outBinds.ret);

                        if (result.outBinds.ret === 1) {
                            console.log("is OK");
                        }
                    }
                }
            );
        };

    db.getConnection({
            user: 'xxx',
            password: 'xxx',
            connectString: 'localhost:1521/XE'
        }, executeOnDb);

})();