Apple Pencil 2015

I have recently been given an Apple Pencil 1st generation [2015 I think it is]. I purchased an adapter from the Apple Store in order to connect it to my iPad Pro. For some reason, when I connect the pencil to the iPad via the new adapter, I get a message on my screen telling me that this device is not supported. To say that I am annoyed/frustrated is a huge understatement, I try to be a good boy by purchasing GENUINE APPLE PRODUCTS, can someone please explain what is happening here ?????