I bought this add-on in order to add k2 links to the sitemap and also to generate automatic meta tags for the k2 items, is it supposed to do these functions or not?

What is the best practice to create a sitemap for a large website? I'm trying to get this job done, but unfortunately, I didn't succeed.

Automatic SEF URLs: 159033 "for the moment.. this should be >1 million very soon whenever the site is crawled"

Please tell me what should I do in this case.

Thanks in advance for your help.