How do I configure wired backhaul

[Lpa66]

I have one satelite with this router which is maybe 40 ft away and upstairs directly above the main router. I do have the satelite connected with an ethernet cable.and from the phone app it shows it is connected with a dashed line which I think means it is connected wirelessly.  Download is around 115 Mb and upload around 12 Mb. How do I set up the wired backhaul? I am running V2.1.4.16.  I have looked at a lot of threads but cannot find the step by step to connect the wired backhaul. Any pointers?

[FURRYe38]

First set up the satellite via wireless. Can do this near or in same room as router. Get the BLUE led on top to turn on. When you see this, connect a known working LAN cable from the satellite to the router. The top led will probably pulsate on and off white. Then may change to Pink, then eventually turn BLUE. Give 5 minutes for this process. Once the top led is BLUE, you can test it by connecting a wired device to it and check internet access, or turn the satellite OFF and move it to its remote location where there is the main LAN cable connection placed there back to the router. Connect the LAN cable there to the satellite then turn on the satellite. The top led should come on BLUE.