Alias to server_ip/drupal

Server NGINX
1

Hello,
i am rather new to the nginx and i have a trobule with alias from my
default
page (http://server_IP/) to the Drupal (http://server_IP/drupal). I got
the
error message: 404 Not Found. I have no idea what is wrong and i didn’t
find
anything with google either. Thanks for your help. These are my configs:

nginx.conf

user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;

events {
worker_connections 1024;
}

http {
log_format main '$remote_addr - $remote_user [$time_local]
“$request”
’
'$status $body_bytes_sent “$http_referer” ’
‘“$http_user_agent” “$http_x_forwarded_for”’;

access_log  /var/log/nginx/access.log  main;

sendfile            on;
tcp_nopush          on;
tcp_nodelay         on;

keepalive_timeout 65;
types_hash_max_size 2048;

include             /etc/nginx/mime.types;
default_type        application/octet-stream;

# Load modular configuration files from the /etc/nginx/conf.d

directory.
# See Core functionality
# for more information.
include /etc/nginx/conf.d/*.conf;
}

default.conf

server {

server_name  46.101.231.239;
root   /usr/share/nginx/html;
index index.php index.html index.htm;

location / {

alias /drupal/;
try_files $uri $uri/ =404;
}
error_page 404 /404.html;
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root /usr/share/nginx/html;
}

location ~ \.php$ {
    try_files $uri =404;
    fastcgi_pass unix:/var/run/php-fpm/php-fpm.sock;
    fastcgi_index index.php;
    fastcgi_param SCRIPT_FILENAME

$document_root$fastcgi_script_name;
include fastcgi_params;
}
}