Sitemap URL in Robots File & Sitemap Frequency

[Alfuzzy]

I would like to add sitemap URL info to my Robots.txt file. I believe I see XF sitemaps are located in:

www.mysite.com/internal_data/sitemaps/

And then the sitemaps are in multiple files with the format of:

sitemap-1234567890-1.xml.gz
sitemap-1234567890-2.xml.gz
sitemap-1234567890-3.xml.gz
sitemap-1234567890-4.xml.gz
sitemap-1234567890-5.xml.gz
sitemap-1234567890-6.xml.gz

What's the proper URL & format to add to my sites sitemap to the robots.txt file?

Also...is there a setting in the XF Admin CP for changing the frequency of auto submission of sitemaps?

Thanks