Conclusion, maybe my problem was bind a standard port.

To add your desired port use this command:

sudo semanage port -a -t http_port_t  -p tcp [yourport]

Now run nginx with sudo:

sudo systemctl stop nginx
sudo systemctl start nginx

This should solve the problem:

setsebool -P httpd_can_network_connect 1

Option #2 (probably more secure)

setsebool -P httpd_can_network_relay 1