These FlexRip tasks were declared 'Soon outdated' in AE 23.07.
RIP IMP File to Screened and Unscreened Tiff File (Soon Outdated)
RIP to Screened and Unscreened PostScript File (Soon Outdated)
The alternative is to use Imaging Engine, Esko's more recent RIP and Proof application, based on Adobe technology.
The product Imaging Engine has its own documentation pages.
Its user guide is also added to this AE complete manual as a chapter: RIP'ing with Imaging Engine.