Hi,
for ssh over ethernet you must be sure that your computer’s ip is on the same network as the your router’s ip. If the router’s DHCP is still functioning, connect via Ethernet cable, you will receive an IP address from the router automatically. If you have OS Windows, you can check it with the command ipconfig -all, if you see an IP from the range 198.168.8.XX and as a gateway an IP 192.168.178.1, then the router’s DHCP is still working, go to the SSH step, if not, you have to set computer’s IP address manually.
SSH Access via powershell use the command: ( you can copy/paste)
ssh root@192.168.8.1
if the ssh service on the router is active, after the key exchange you will be connected automatically if no password has been set.