How does Moz DA and Ahrefs DR metric manipulation currently work?

I see some people selling DA and DR manipulation services on FB and SEO forums. I'm curious how this works. Is this still with URL redirects such as

http://maps.google.ad/url?sa=t&url=https://www.example.com
Because I was told that was patched. Any idea how its done now?

Read https://www.blackhatworld.com/seo/da-pa-manipulation-tool-free-simple.1322186/