The web server does not open the source and displays an error-like screen.

I am creating a web environment using nginx and php-fpm.
I got an nginx error when I tried to open the web by mistake.

We reviewed the nginx and php-fpm environment settings, set up and reboot automatically.
However, the following error appears:

I can't think of any idea to fix it because it doesn't change even if I try many things.
I would appreciate it if you could let me know if you have experience.

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Faithfully yours, nginx.