No link to sitemap.xml in robots.txt

Hi,
I use sitemaps in SmartCrawl. But there is no link to sitemap.xml in robots.txt

https://www.zijemehomemade.cz/robots.txt

Is it necessary to set it in some advanced settings or so? I didn't find nothing like that (and think SmartCrawl should do it automatically...)

Thanks,
Jiri