To get your WhatsApp backup from Google Drive, follow these steps: first, make sure that your backup setting is on in settings>chats>chat backup. Uninstall WhatsApp and go to the Play Store to reinstall it. When installation is done, start the app and verify your phone number. After it, follow the screen prompts, and when it says “backup chat history,” tap on it to back up your chat from Google Drive. If you want to know more about this topic or similar ones, click here.