Why doesn't it see files in a different directory or is the format wrong?

Question

Nginx

Why does nginx not open the page when you specify the path root /home/user/nginx/
where the index.php files are located, error 403
And when you specify /root/var/www/html index.nginx-debain.html everything displays

Answer 1

I suspect that there is a permissions problem and Nginx is not allowed to read the index.php file. And if this page should be displayed not by Nginx, but by a PHP interpreter - perhaps the access rights do not allow it to read this page.
Try replacing "index.php" with "index.html" or "index.nginx-debain.html", it should more likely help.
PS For error monitoring, in *nix programs, and in Nginx in particular, there are such things as "error log" and "access log".