Router A is connected to router B. Router A's LAN interface is connected to router B's WAN interface. The two routers are cascaded.
DHCP is enabled on router A, dynamic IP addresses are configured for the WAN interface on router B, and the gateway of the LAN interface on router B is not on the same network segment as that on router A to avoid IP conflict.
For example, if the gateway IP of A is 192.168.1.1, change the gateway of B's LAN port to 192.168.2.1, that is, at least one of the first three must be different from that of A.
The router wireless Settings are set according to the instructions. After the configuration, the LAN port of route A is connected to the WAN port of route B.
The wireless Settings on both routers are set to the same ssid and password.