In WordPress, there are plugins to build sitemaps like Jetpack, Yoast SEO, All in one SEO, MSN sitemap, etc. However, the sitemaps should be validated on Google search console and may need to be fixed if there are any errors or unwanted nodes in XML sitemaps.
Read more – Build & Submit Sitemap
How to submit and validate sitemaps
This will need access to the Google search console.
Normally it will submit it successfully and can be read by Google on the next Search Engine Crawl, after this the submitted pages will be indexed if they are valid pages. If the pages are not valid they will be shown under: Indexing > Pages