You need a reader that reads ABS codes. Not all of them do. This is likely a fault in the ABS system, but cant be sure until you read the ABS codes. I had something similar years ago and it was a portion of the ABS wire harness being frayed somewhere, probably from when I installed the lift and cranked on things.
https://a.co/d/iIcMn5j
This is the one I have that reads ABS.