JS error as: var is not defined. How can i send value on function

Now I have this code to create sitemap.xml when I run /sitemap.xml

 database = firebase.database();
    var ref = database.ref('urls');
    ref.on('value', gotData, errData);

    function errData(err){
        console.log('Error!');
        console.log(err);
    }  


function gotData(data){
        result = data.val() 
        return urls = Object.keys(result)
                     .filter(key => result[key].last_res > 5)
                     .map(key => ({url: '/' + result[key].url_site + '/'}))
    }

when i try running console.log(urls) in gotData(data) function, it returns as

{ salmon: 
   { count: 1,
     last_res: 10,
     url_site: 'salmon' },
  'salmon-food': 
   { count: 1,
     last_res: 601,
     url_site: 'salmon-food' } }

I need to return 'urls' in gotData(data) to create sitemap.xml.

var sitemap = sm.createSitemap({ 
            hostname: 'xxx.com',
            cacheTime: 600000,
            urls: urls

        });
app.get('/sitemap.xml', function(req, res) {
    sitemap.toXML( function (err, xml) {
        if (err) {
            return res.status(500).end();
        }
        res.header('Content-Type', 'application/xml');
        res.send( xml );
    });
    });
}

But now its error on var = sitemap as

urls: urls -> urls is not defined

So how can I fix it?

via Moomoo Soso