How to set up proxy over VPN?

Question

VPN

Actually in addition to this question How to start up a headless browser through a specific network interface?
As far as I understand, it is not possible to launch a headless browser through a specific tun interface, but it is possible to create several proxies, each of which will go through one of these interfaces and the browser itself will already be launched through a proxy. Tell me, please, where to dig. I've never dealt with proxy settings before.

Answer 1

For 3proxy
proxy -i127.0.0.1 -p1001 -e192.168.0.1
proxy -i127.0.0.1 -p1002 -e192.168.0.2
proxy -i127.0.0.1 -p1003 -e192.168.0.3
proxy 127.0. 0.1:1001 uses external address 192.168.0.1, 127.0.0.1:1002 - 192.168.0.2, 127.0.0.1:1003 - 192.168.0.3

Answer 2

forum.ixbt.com/topic.cgi?id=7:24577
python2or3.blogspot.com/2017/03/vpn.html
+ Google VPN +Proxy

Answer 3

It is possible, but difficult. Specify a route to an address through an interface.

Can you give more details? The route to the address is the ip of the site that I will be parsing?
The problem is that I can’t use one vpn statically. It is necessary that requests for different pages go through different vpn. With simple sites that you can just parse without tricks - just randomly select localAddress for each request from the list of running VPNs