There aren't a lot of post-processors available for lathes, it seems. Here's a rather old article about them:
https://www.ptc.com/en/support/article/CS314943
If your lathe has the same Fanuc model as one of those listed, maybe you can tweak the provided files to give you the exact results you want.
I've not had the privilege of using an NC lathe, so I don't know what is necessary to get programs formatted for them. Probably they are like mills in that there are basic commands that are the same regardless of the machine maker, but the tough part is the "M" codes and any special "G" codes.
