According to the XDA Developers, HMD Global has made the Android P beta 2 available for the Nokia 7 Plus. The developer preview program is to allow app and product developers to test out the latest software in order to optimize apps for it. The software is extremely unstable and lacking in many key features, considering that it is an early version of the next edition of Android. ( XDA mentioned problems accessing SD card data).
If you still want to get how the new software looks on the Nokia 7 Plus, you can sign up at the Nokia Developer Section to get started.