wireless link with 2 ISPs

Hi,
I have a wireless link with 2 RouterBox433 which connects my office to a remote place where 2 DSL modems are connects me to internet.
I want to my 2 internal networks access the internet through these 2 different remote modems.

  1. Router1(192.168.4.1) should route through Modem1(192.168.1.1)
  2. Router2(192.168.2.1) should route through Modem1(192.168.3.1)
    What is the exact configuration on RB433 boxes to route?
    I tried to configure but both networks route through Modem1 only.

Thanks and regards.

check the manual for routing policies