object buffer for hair

I’m trying to get a OB for hair and I saw this in a previous discussion…

You can switch the Render option in the Hair Render tab to Raster (Post) - then you’ll get a Multi-Pass tab where you can set the Alpha to Separate. Then if you create a Multi-Pass for Post Effects, you’ll get an Alpha layer for the hair.

I don’t see a “Raster (Post” in the Hair render?

Other tips on getting an OB for hair?  Working on v17studio

Thanks,
Tom