Make a locally hosted WP pointed by a WP bought domain

Hi all,

I’m new to the forum, and I hope I’m writing this post in the correct place.
So, I have a wp instance installed on a server of mine. Let’s say this server is reachable at the domain my.server.domain . It runs an ngix http server.
The wp is installed and accessible at my.server.domain/page86 .

In parallel, I have a domain I bought through WP, which is page86.org, where I have my online version of WP (which I used at the beginning).

Now, I’d like to have the domain page86.org not pointing at the online version of WP, but at my server, namely my.server.domain/page86.

How can I do that? I already messed up the DNS on page86.org.

Many thanks

The page I need help with: [log in to see the link]