VRChat does not work as bonelabs, the avatar data and whatnot is not held in your device as is, but on the API. If you wish to upload an avatar, you need a computer, with the compatible unity client and the SDK. The avatar file itself (the blueprint) needs to go through a security file check on the other end (the upload process/VRChat SDK API), and once its validated, the avatar is assigned to your profile ID, hence why people can't clone a private avatar unless theyre using either malicious clients, or getting it directly from the cloud itself, which is what RipperStore does.