New version in Debian archives ? RPi

…If I install Sonic-Pi to a RPI (latest Raspbian)
It is version 2.1
Although the preinstalled (full desktop) version is 3. ??(latest)
How can I access the latest version to install on RPi ???
Even the version on the Sonic-Pi site is 2.1 …

The Sonic Pi package on Raspbian (and all Debian derivatives for that matter) is not maintained. If you want to access the latest version, you have the option of building the package from source code. There’s a big thread going on about it here