XML Sitemap Generator for WordPress 4.0.8 not working

I’ve tested this in Google Search Console and I keep getting error messages. Google does not acknowledge the site exists and the xml sitemap is not working. I’ve tried all day to get it to work, but have no clue. I am not a tech coder and don’t understand all of the docs I’ve read for it. Please help asap. Thank you.

https://www.ads-software.com/plugins/google-sitemap-generator/