You cannot have both the official app and a modded app with the same phone number. Allow Unknown Sources: Go to your Android Settings > Security > Enable "Install from Unknown Sources". Download the APK:

Before making any changes, ensure you have backed up your WhatsApp chats. This can be done through the app's settings or by manually copying the chat database.

Before installing, use a tool like to check the MD5 checksum. A clean GB 6.85 APK should have an MD5 similar to: c8d3a1f9e2b4c7d5a6f1e3b9c8d2a4f6 (Note: This is an example; find official community hashes on XDA Forums).

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