My iMac can't connect to the internet.

I have changed my router recently, because the previous was failing to maintain the connection with my devices.

The one I have now is the TL-WR941ND V5. I setup the Wi-Fi easily and could connect all my devices to it, and could connect to the internet, but my iMac.

When I try to connect it says that the IP can't connect to the internet, but all my other devices can. Is there anything I can do?

I already tried turning the router on and off, I already tried using the previous router, but kept having issues with all my devices.