For a general SKR1.4(T) config see https://github.com/Klipper3d/klipper/blob/master/config/generic-bigtreetech-skr-v1.4.cfg
For some general troubleshooting tips see: How-To Trouble-Shoot
This indicates that your [mcu] either is wrong or your board is not correctly flashed / connected. The [mcu] section must match the output of ls /dev/serial/by-id/*