Use a tool like balenaEtcher to flash the EmuELEC .img.gz file to your SD card.
Look at the sticker on the underside of your console. For example, the "X-L" model often requires the 905L chipset dtb. super console x dtb.img
The OS boots! You can play Mario, but the Wi-Fi settings are greyed out. The dtb.img you are using does not have the correct driver mapping for your specific Realtek or Broadcom Wi-Fi chip. Use a tool like balenaEtcher to flash the EmuELEC