If WhatsApp does not have access to your Contacts, the easiest way to restore the permission is to uninstall WhatsApp and reinstall it.
Before uninstalling, make sure your WhatsApp chats are backed up to iCloud. Go to WhatsApp → Settings → Chats → Chat Backup and verify that a recent backup is available. This is important because uninstalling the app can remove locally stored WhatsApp data, and you will need the iCloud backup to restore your chats and media.
After reinstalling WhatsApp, during the setup process, it may prompt you to grant access to different features such as Contacts, Photos, Camera, Microphone, and Location. Grant these permissions according to your requirements.
For example, enable Contacts if you want WhatsApp to access your saved contacts and display them in the app. Allow Photos if you want to send or access photos from your library, and enable Location only if you use WhatsApp's location-sharing features.
If WhatsApp does not prompt for a particular permission after reinstalling, you can check and enable it manually under Settings → Privacy & Security or Settings → Apps → WhatsApp, depending on your iOS version.
The important point is: back up your WhatsApp chats to iCloud first, then uninstall and reinstall the app.
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