How to properly implement vpn proxy chain?

Question

linux

Hello.
We use luminati.io as a proxy for our requests. This service asks the user to provide a username and password, which, unfortunately, cannot be specified on mobile devices. The advantage of luminati is that you can add "-country-de" to the username and German IPs will be used.
It seems that the only way to resolve this situation is to use a VPN, since you can already specify the username and password there. But here the question is, what vpn and how to use it so that there are dynamic usernames, and how inside the vpn, depending on the username, use a proxy with the necessary login and password?
username-country-de => VPN => proxy: username-country-de:[email protected]:8080
username-country-us => VPN => proxy: username-country-us:[email protected]:8080
Thanks!

Answer 1

openvpn route

Answer 2

3proxy parent

Answer 3

Raise a local proxy without authorization, on which configure the parent proxy with authorization. For example for 3proxy

auth iponly
allow *
parent 1000 http proxy1 user1 pass1
proxy -p10001
flush

allow *
parent 1000 http proxy2 user2 pass2
proxy -p10002
flush

allow *
parent 1000 http proxy3 user3 pass3
proxy -p10003
flush

Raises a proxy on ports 10001 with forwarding to proxy1, 10002 with forwarding to proxy2, 10003 with forwarding to proxy3, you can choose the country through the proxy port selection.