I would advise using Nginx infront of it.
You can google NodeBB Nginx Config and you'll have one you can copy/paste.

Nginx will then be on port 80 and you can close 4567 on your FW.

I have a new forum (also looking for mods ) which is the Pokemon Go Forum @ http://www.clubcatchthemall.com.

The sitemap is available @ http://clubcatchthemall.com/sitemap.xml

As you can see It displays the following data....

<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
    <sitemap>
        <loc>
            http://www.clubcatchthemall.com:4567/sitemap/pages.xml
        </loc>
    </sitemap>
    <sitemap>
        <loc>
            http://www.clubcatchthemall.com:4567/sitemap/categories.xml
        </loc>
    </sitemap>
    <sitemap>
        <loc>
            http://www.clubcatchthemall.com:4567/sitemap/topics.1.xml
        </loc>
    </sitemap>
</sitemapindex>

The site is hosted on port 4567, but nginx proxys to localhost:4567 and is open on port 80.
All the other URLs work just fine.

How can i get these to display correctly? I tried amending the config json file but it seemed to take the site down.