Need some remote help to configure router

I recently switched broadband providers and the setup I have is like this: main router connected upstairs, 2nd router downstairs connected via Ethernet port (lan to wan) to the main router. Prior to switching providers all was working ok after the switch 2nd router stopped working and I’ve been trying to figure it out to no avail. Need someone to help me set it up and get it to work. Can’t pay you for it if it does not work