The Volirium P1 currently reads airspace files in the OpenAir format. To download these files we recommend Soaringweb. After clicking on your region and country, you are presented with a number of formats to download. Choose OpenAir format as shown below. In order to load airspaces onto your vario, you need to connect the vario to a computer Data management|via USB, drop the files in the folder "airspaces" and then select an airspace file to be displayed on the Volirium P1.
Unfortunately, downloading the OpenAir files from SoaringWeb does not work for the UK. You have to download the ASSelect program as shown below. When generating your file with the program, make sure you select the OpenAir format at the very end. The program seems to be available for Windows only.