The Y endstop mount that comes in the kit is not correct for what is provided in the kit. Use the printed replacement from FYSETC Github

Using 2x M2.5x8 socket head screws mount the Y Endstop to the Y Endstop mount

Mount the Y Endstop to the frame with 2x M5x10 button head screws and 2x M5 T-nuts

The Y Endstop will be 60mm from the inside of the back 2040. Basically the back of the endstop mount should be in line with the cross 576mm 2020

FYSETC manufactured a new Y endstop mount for the metal kit. I do not know when they started including the part in the kit.

To mount use 2x M3x8 button head screws and 2x M3 T-nuts. -More info to come