beginner : basic question to understand an application

Hello,

I'm a beginner in nginx and I have a server to manage. This server was given us everything configured so we did not do the installation.
This server responds to the web request below but the documentation is very incomplete and I have to use it in an application, but I want to know if this request takes parameters. The company can not help us so I have to look directly into the files but I do not know where they are so I try to "go back" the request to the file

URL : https://{mydomain}:666/api/v1/example/debug/CallLogs?example=1

After some research I found that a proxy is returning the web request on localhost:81 and the process on this port is nginx
I looked at the nginx configuration and I found this, can you tell me if I'm right or if I missed something :

/etc/nginx/nginx.conf define an http block containing "include /etc/nginx/sites-enabled/*"

/etc/nginx/sites-enabled/ contains only one file named "default" that defines a server block :
define two listen port : "listen 127.0.0.1:81;" and "listen 127.0.0.1:444 ssl;"
a little further it define the server name as "_", the root as "/var/www" and the index on "index.php"
again a little further it define the /api/ location :

location /api/ {
try_files $uri /api/index.php$is_args$args;
}

This location says to nginx to :
1) search a file /var/www/api/v1/example/debug/CallLogs
2) search a file /var/www/CallLogs.html
3) go on file /var/www/api/index.php?example=1

Is that right ? I ask this because I can not debug /var/www/api/index.php and I can not find the first 2 solutions

Thanks in advance