Why can't I load Steam's verification code after using a proxy, but if I don't use a proxy, or use a Russian IP he can display the verification code normally, I am confused about this.
For those who needs this later, you can set up http proxy and send a simple get request to https://api.ipify.org , it will give you the ip adress in plain text, no need to parse the json.
One of many simple and easy ways to do it.