[Plugin: Google XML Sitemaps] No www prefix in site map

Hi, I have submitted my site map to google but I get the error message below when I log in to Google webmaster tools:

“We’ve detected that you submitted your Sitemap using a URL path that includes the www prefix (for instance, https://www.example.com/sitemap.xml). However, the URLs listed inside your Sitemap don’t use the www prefix (for instance, https://example.com/myfile.htm).”

can anyone help me get by this? Thanks. -Mark

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