PPTP server with shadowsocks

I have installed shadowsock and PPTP server on my openwrt router

I want to share my shadowsocks through PPTP server

now the problem is my client connect to sever but router not sharing shadowsocks and share wan internet.

Tunneling PPTP over Shadowsocks looks like not possible:

Tunneling Shadowsocks over PPTP may be possible, but I have no experience with Shadowsocks.