How to raise a proxy from the phone?

Question

proxy

How can I raise a proxy server from an android smartphone?
I found the ultimate servers program https://play.google.com/store/apps/details?id=com....
It performs the task. But how to make the proxy accessible from the Internet?
The phone's ip is grey. As I understand it, you need to use services like ddns, etc. But I don't know exactly how.