The official way to register for and download the beta is through the application. Follow these steps to initiate the process: How to install HarmonyOS 4 on Huawei P50 Pro Global Version
HarmonyOS 4.0 is a major leap in Huawei’s operating system journey, introducing a revamped "Live Window" (similar to Apple's Dynamic Island), personalized emoji wallpapers, and the significantly faster Ark Engine. While stable versions are now rolling out for many flagship devices, early adopters can still join beta programs to test the latest incremental improvements before they reach the general public. harmony os 4.0 beta download