You need to look in pin.h and swap the definitions from Z to E4 for your board
type 68 in Marlin, Your E4 etc is defined here [github.com]
Z is here [github.com]
swap the enable, step and direction lines.
type 68 in Marlin, Your E4 etc is defined here [github.com]
Z is here [github.com]
swap the enable, step and direction lines.