Submitted URL not found (404)

Have you been getting this error consistently for a while?
Bc my first impression is that it simply timed out for whatever reason.
It’s being captured and indexed fine :
https://dreamcovers.com.au/product-sitemap.xml

https://search.google.com/test/rich-results?id=CUpbic01wYcEBWu83FiVTA

I would ignore it for now – but you may want to ask in more appropriate support forums that are intended for SEO, Google search console, etc.