Paste your URL list, then set a priority and changefreq per entry, and the tool generates a valid XML sitemap ready to upload to your site root.
Place it at your site root (e.g. yoursite.com/sitemap.xml) and submit that URL in Google Search Console and your robots.txt Sitemap line.
Yes, as a starting point — double-check paths, URLs, and directives against your actual domain before deploying.
No. Everything is built client-side in your browser from the values you enter.