How to use sitemap and what is better sitemap XML crawler?

Try this, I use it for years. It works. Use free plan only if you don't have money just like me 😝

https://sitemap.freeadsgroups.com

Submit to Google Search Console ( GSC) and Bing / Yandex webmaster manually then for faster indexing with format:

https://www.myblog.com/sitemap.xml

Change "myblog" with your blog URL, Don't use duplicate Top Level Domain ( ex: .com) otherwise you get error message. Click "Create" then "Submit" button. When finished at Pro Sitemap go to GSC etc... and so on.