We checked on the sitemap at https://autoskup.biz/sitemap_index.xml and currently this is returning a 404 error so we aren’t sure if you are still using the XML sitemaps feature of the plugin.
If you are receiving a message in Google Search Console that it cannot fetch the sitemap we suggest the following actions:
1. Clear all your caching from your theme, plugin, server, CDN like CloudFlare or browser. If you are not sure how to clear caching from theme/plugin please speak to those authors. If you want to clear cache from the server, please speak to your host provider. To clear the cache from a browser use this guide: https://kb.yoast.com/kb/how-to-clear-my-browsers-cache/.
2. Delete your sitemap in Google. Doing so will not hurt the SEO of the site. This guide explains more (scroll to the bottom): https://support.google.com/webmasters/answer/183669?hl=en.
3. Submit the sitemap again. Be sure to submit only sitemap_index.xml and nothing else. This guide explains more: https://kb.yoast.com/kb/submit-sitemap-search-engines/.
4. Edit your robots.txt to remove your sitemaps. This guide explains more: https://kb.yoast.com/kb/how-to-edit-robots-txt-through-yoast-seo/
5. Monitor the results to see if more pages get indexed
