How to connect a machine from one local network to another machine in another local network

everyone,

At home, I have a router/modem which gives local network addresses via DHCP in range 192.168.1.0/24 (network A). This network provides also wifi to part of my house.

To this local network I have plugged a wifi range extensor, which in turn gives me another set of local network addresses via DHCP (network B), in the range of 192.168.0.0/24. This range extensor provides ethernet/wifi to another part of the house.

So I ended up with two wifi local networks. No problems with mobile telephones, since they switch easily.

However, I set up a home server in network A with address 192.168.1.100 (static address), which I cannot reach when I need to access resources from my desktop ethernet-connected computer in network B.

I’m not that savvy in networking, so I please ask for help from gurus here.

How can I ssh, access nextcloud or access NFS exports from desktop in network B to home server in network A?