Solved: Ipv4 and Ipv6 (Router and Modem)

I went into the Router configuration page and messed something up by mistake in the IP address I think.

When I connect my wire to the modem, I have internet on my pc and don't have WI-FI but when I connect the wire to my router I don't have any internet connection.

I cannot go to my router configuration page since I will not have any internet connection when connected to the router.

Please help.