Hi Stefano. As Derek said, the PayPal Payments Pro Add-On (which uses the PayFlow API) is deprecated. But it is still available for download here:
https://www.gravityforms.com/my-account/downloads/
(it’s at the very bottom)
There was a PayPal Pro Add-On available before PayPal Payments Pro, but that was retired a long time ago.
The PayPal Checkout Add-On uses the latest PayPal Commerce Platform API, and is the only PayPal add-on that will be supported going forward.