Copying Tomato firmware/interfaceto identical router model

Hi,

I'm total new in using Tomato and copying it to another device.

I would like to copy the Tomato firmware from one Asus RT-AC66U to a new identical model.
On this one router there is a tomato firmware that gives you the ability to adjust some specific settings of the router, it's a bit custom made I guess. So I'm a able to download/export this custom interface and put it on a new router?

I have read things about "nvram" but I'm first of all wondering if some can give me some...

Copying Tomato firmware/interfaceto identical router model