I know about page URL canonicalization but what is about sitemap canonical, I found 3 different formats for XML sitemap like: https://www.example.in/sitemap.xml http://www.example.in/sitemap.xml http://example.in/sitemap.xml
Your XML Sitemap should only contain URLs you wish for search engines to index. If a URL is canonicalized, this is an explicit statement to search engines that you do NOT wish for the URL to be indexed, and instead wish for the canonical URL to consolidate indexing signals.