Google Search Console – Your sitemap or sitemap index file does not correctly declare the namespace!


Here is my site map, it starts like this:








    
        https://autocostos.info/AR
        weekly
        

            
            
            
            
            
            
            
            
            

But the Google search console insists that

Your sitemap or sitemap index file does not correctly declare the namespace

They just give an example on line 16:
Line 16
Parent tag: url
Tag: link

Line 16 corresponds to

What am i doing wrong?