It’s a bit confusing! The [product|IF188-150] carries both the keyboard and trackpad data to the logic board and that other cable is the power lines for the keyboard backlight which you can see here [product|IF188-158]
The small logic board these cables connect to is the [https://www.ebay.com/itm/166685182506?|2020 Keyboard Trackpad Board 820-02288-A] I don’t think the keyboard backlight or the keyboard cables are replaceable. I would just replace the fully uppercase assembly as it’s a lot less work and less of a risk of damaging things, you would still need the Keyboard Trackpad Board if it’s damaged.