my website ip is blocked by site I want to fetch data from it .. how to proxy it

hi all,

my site fetch data from site2
and site2 blocked my site ip

is there anyway to change ip address of my script to access site2 again (while I'm stay on my site ip)

another way, how to change the ip address from running script, to cross domain ip to another ip . that can access the site which is blocked my ip (without changing hosting ip address)

my nginx config


upstream backend {
server unix:/cls/php-fpm.socket;
}

server {
listen *:80;
server_name www.sub.domian.com sub.domain.com ;
rewrite_log on;
location / {
root /home/storegem/public_html/;
index index.php index.html index.htm ;
}
location ~* ^.+\.(jpg|jpeg|gif|css|html|png|js|ico|bmp|zip|rar|txt|pdf|doc)$ {
root /home/storegem/public_html/;
expires max;
access_log off;
}
location ~ ^/.+\.php {
fastcgi_pass backend;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME /home/storegem/public_html/$fastcgi_script_name;
fastcgi_param PATH_INFO $fastcgi_script_name;
include /etc/nginx/fastcgi_params;
}