Hi Sebastiano:
Fluent ROM building is a Beta Feature in 2023R1 and is described in the beta section of the Documentation. In it a Fluent cell can be hooked up to Design Exploration 3D ROM cell :

https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v231/en/fluent_beta_doc/flu_ug_rom_manual_snapshot_production.html
I am not sure if Polyflow ROM can be converted using this method, however.
Best Regards,
Judy