From the SEO Boost menu, click on sitemap.
At first use, you should configure your module :
Choose the update frequency, check or not the inclusion of images.
You can also exclude “system” pages from the sitemap.
Finally, click on generate the sitemaps : you will see some links pops at the top.
You can use the main sitemap and import it into the google search console (ex webmaster tools).
Note that if your website is multilingual, each language will have its own sub-sitemap.
You can automate the sitemap generation by adding the link provided in the automatic creation section into a CRON job.