I believe we have all heard that China recently released a new operating system "Harmony NEXT", which will no longer be compatible with Android .apk files, and needs to develop a separate version for this system, hoping that the ProtonVPN team can develop a Harmony version of ProtonVPN (file suffix .hap) in the future, and truly make it a VPN that supports all platforms (even if it can't be directly put on the official app market "App Gallery", It is also possible to sideload the installation package to work fine on "Harmony NEXT")