How to forward a port through 2 routers?

Question

System administration

There is a router in which a SIM card is installed from an operator with a white IP address. This router has only one output, which goes to the WAN port of another router, respectively, the second router already distributes the Internet to other computers on the network.
I need to make it so that I can connect from outside to a computer that is connected to a second router.

On the first router, the LAN address is 192.168.1.1
On the second router, the LAN address is 192.168.0.1 and WAN 192.168.1.2
Something I don’t understand how to do the forwarding correctly.

Scheme: https://drive.google.com/file/d/1b8rt_QBJupt-Oas3r...

Answer 1

Why do you need two nats? Why is the first router not in bridge mode?
Just two port forwards: On the first one to 192.168.1.2 (to the second router). On the second, it is already forwarding to the target computer.

Answer 2

Set up unconditional port forwarding twice.
On the first - From the Internet to 192.168.1.2
On the second from the Internet to the ip of the desired computer.