502 bad gateway with nginx

I used the sample config file from the docs and changed a few params to match my versions and folder/file names but I get 502 bad gateway from nginx. SO I might have missed something:

events {
  worker_connections  1024;  ## Default: 1024
}
http {
server {
    listen 80;
    listen [::]:80;
    server_name laravel-backend
    root /home/user/www/my-app/laravel-backend/public;
 
    add_header X-Frame-Options "SAMEORIGIN";
    add_header X-Content-Type-Options "nosniff";
 
    index index.php;
 
    charset utf-8;
 
    location / {
        try_files $uri $uri/ /index.php?$query_string;
    }
 
    location = /favicon.ico { access_log off; log_not_found off; }
    location = /robots.txt  { access_log off; log_not_found off; }
 
    error_page 404 /index.php;
 
    location ~ \.php$ {
        fastcgi_pass unix:/run/php/php8.1-fpm.sock;
        fastcgi_param SCRIPT_FILENAME $realpath_root$fastcgi_script_name;
        include fastcgi_params;
    }
 
    location ~ /\.(?!well-known).* {
        deny all;
    }
}
}