Forward api call from one gateway to another gateway

Hi All,

I am trying to achieve this flow for my api.
Api call to intranet backend —> internet Gateway 1 —> forward api call —> intranet Gateway 2

How do i go about making an api call from one gateway to another gateway ?
I keep getting a 404 error.
I tried having them listen to the same path, but gotten a Listen path collision error

Thank you