Google Search Console – Sitemap could not be retrieved

I'm trying to submit my sitemap on my Google console, but every time I add it, I've always been told that the fetch was not possible. I've uploaded my sitemap.xml to my domain root, but Google still does not see it. Please, how can I solve this problem? I spent the last two days with it and it's like I'm going into the circle.

Below is my full URL

My sitemap is in the public_html folder named sitemap.xml