Router with OpenWrt as second - can't use services from main router

Hi, using archer c7 as my second ruter, but my home server is connected to first one which I got from provider, and I have many services on first one. All starts with: 192.168.178.x, but on second all starts from 192.168.0.x . So if I am connected to second one I can not connect to services from first one.

Can I fix this?


convert the 2nd one to dumb AP, or start opening ports in the firewall.

make sure they're on the same subnet - 192.168.178.