Sitemaps - how do I generate one?

I am way back on ver 3.5, but even there when I download the code there's no sitemap for seo

How do I generate one?

I know I can use 3rd party but I have over 70,000 urls so I would have to buy a pkg just to do a site for SEO

Any suggestions?

PS: perhaps this belongs under the other forum but seems a setup/config thing

Just go to your site with url - e.g.  http://demo.nopcommerce.com/sitemap.xml  

But, read this https://www.nopcommerce.com/boards/t/21496/create-sitemap-that-has-my-product-pages-in-it.aspx