help plz convert from htaccess to nginx


AddDefaultCharset UTF-8
Options +FollowSymLinks +ExecCGI
ErrorDocument 404 /index.php
<IfModule mod_rewrite.c>
RewriteEngine On
#Hides backend and its static content from all domains except 1
RewriteCond %{REQUEST_URI} !^/index.php$ [NC]
RewriteCond %{REQUEST_FILENAME} -f
RewriteCond %{HTTP_HOST} !^.*$
RewriteRule ^(.*)$ - [R=404,L]
#No script name
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)$ index.php [QSA,L]
</IfModule>