What is the issue?
Sitemaps allow us to give search engines an overview of your site structure, showing them which pages you want to have indexed and found in search results. If you have indexable pages that aren't found in the sitemap.xml, you could be missing out on providing additional ranking signals for those pages.
How to fix
Update your sitemap.xml with each relevant missing URL listed below either. You should then resubmit your sitemap via Google Search Console. Learn more about this in our wiki and product insights.