iTunes
when I start download I tune the massage appear ( its not compatible with this iOS ) I tried all iTunes versions
MacBook Air 13", macOS 10.15
If your Mac is running 10.15 Catalina, then yes there is no longer a compatible version of iTunes for Catalina.
On 10.15 Catalina, iTunes was replaced with the TV, Podcasts, and Music Apps, along with Finder. All iTunes features are in one of these Apps now. Anything you need from iTunes, must now be done in one of those Apps.