TP-Link port forwarding. - how to make everything work?

Question

Computer networks

I don’t really understand networks, but still I hope for your tips where to dig.
Router Model TL-WR940N / TL-WR941ND, Internet comes according to stat. address in wan 192.168.138.0, gateway 192.168.138.1.
There is a network on DHCP 192.168.1.1.
There is a white ip address like 91.xxx.xxx.xxx. You need to forward port 443 from outside to LAN to server 192.168.1.168, for example
, the Windows firewall is configured for incoming and outgoing port 443

Answer 1

There is a white ip address like 91.xxx.xxx.xxx.

1) Where is he? I don't see it anywhere.
2) Where does the address 192.168.138.2 come from? If this is another router, then first you need to forward the port from that router to your router, and then forward the port to 192.168.1.168 on your router.
3) describe in more detail the situation with the equipment, where what is connected, and who has a white IP address. Perhaps it will be easier to disable DHCP altogether on the second router, and write all port forwards centrally to the router 192.168.1.1. Or is it important for you to distinguish between two different 192.168.* subnets?
In general, it seems to me that you call the exit point of the provider with the White address, which is a white IP address only for the provider, but not for you. If this is the case, then you need to use a VPN to bring your computer to the real Internet, or use ngrok. Both words google beautifully.

Answer 2

The issue is resolved through the provider. On request, it forwards everything that is needed. or they offer to write an application for the issuance of 4 address grids of IP addresses, something like this.
Are there any fat cons if you do a forwarding on request? Or is it better to connect this 4 address grid of IP addresses?