hi nodochau, pls test this, it's pretty simple :
... download attached file and remove the *.txt extension
... be sure that LINK variable = face tool turret post
... load it into osp300 lathe + program select
... clamp the material
... manual mode
... put face tool a bit above the material
... on Z, put it where you wish to take the 1st cut
... auto mode + cycle start
tool will start moving down, towards X-, cut the face, then back up, and will put zero
if face is not clean, push cycle start again / kindly