How to set up a subdomain in Nginx?

Question

Nginx

Good evening.
My domain is in CloudFlare. I used to use Apache on the server, but after installing GitLab I switched to Nginx.
How can I properly create a subdomain in it?
/var/www has a chess folder. According to one of the instructions, I added a new host file to sites-available and added it to sites-enabled.
After adding an entry to CloudFlare. When opened, it gives an error 403 (access denied).
Where is the mistake?

Answer 1

nginx config to the studio, there is an assumption that nginx is not running from the user from which apache worked and, accordingly, the nginx user has no rights to access the directory.