UWB Interoperability Specification

May I ask where I can find this document: the UWB Interoperability Specification, Developer Preview, Release 1? This document is a comment I saw in Qorvo's project. I need to understand the specific meaning of the data sent to the iPhone by embedded devices in the Nearby Interaction Access Protocol. I am developing an application based on Qorvo's dwm3000, so I need to understand this aspect. Thank you for any response!