Hello,
We deeply apologize for the unexpected delay in response. This ticket has been stuck in our drafts section for some reason.
We tried to check your sitemap, and it was returning a 404 error. However, we’ve removed the XML caching files from wp-content/uploads/rank-math and now, the sitemap is working properly.
After further checking, we found that the SureCart plugin you’re using on your website is inserting an invalid URL to your sitemap, and that’s why you’re facing the issue on Google Search Console:



We’ve also added a screencast in the sensitive data section for your reference.
In order to resolve the issue, please get in touch with the plugin support and inform them about this issue.
We went ahead and checked some of your posts and pages as well, and found that you’re using custom canonical to these posts and pages:

Please note that we don’t add posts/pages/products with custom canonical on the sitemap because usually, when people do that, it is to prevent duplicate content, so we remove the pages with the custom canonical.
You can follow this URL for more details: https://rankmath.com/kb/url-not-in-sitemap/#custom-canonical-url
If you want to add the posts and pages to your sitemap, you’ll have to remove the custom canonical from Rank Math SEO meta box, Advanced tab, and let Rank Math generate the self-referencing canonical, and after that, your posts and pages will be included in your sitemap.
Let us know how it goes. Looking forward to helping you.
Thank you.