Plasma Auto Z zero

I am the new on SheetCam. My problem auto z zero. the Gcode from sheetcam is G28.1 but mach3 need G31 and i do not know how to edit Gcode please help me

What post processor are you using? Most plasma posts can be configured to use either g28.1 or g31. Go to Options->machine->post processor and click on the ‘edit post’ button. At the start of the file you will probably see a number of configuration options, one of which will be which probing method to use.

Thank for your reply
I used Mach3 plasma post

Are you sure you are using Mach3 plasma? That post doesn’t use either G28.1 or G31.