Program through a network card?

Question

Browsers

I did not know how to ask the question correctly, so here's the task: It is
necessary to allow outgoing / incoming traffic for Firefox through another network card. That is, there is a physical network card and a wafer, firefox should work through a wafer. Is it realizable?

Answer 1

Set Firefox to use a proxy.
Add a route to the proxy address with an explicit interface.

Answer 2

bilee.com/2212.html