On WhatsApp, once a message is deleted by the sender, there’s no official way to view it directly within the app. WhatsApp’s privacy rules don’t allow users to recover or bypass deleted messages.
That said, people commonly use a few workarounds (with limitations and risks):

Notification Log (Android only)
On Android, notifications are saved in the system log.
You can access it through:
Built-in "Notification History" (available on many newer Android phones under Settings > Notifications > Notification history).
Or third-party apps like Notification History Log or Notisave (they capture notifications before messages are deleted).
Limitation: Only works if the message appeared in your notifications before being deleted.
Backup Restore
If the deleted message was backed up in your last WhatsApp backup, you can uninstall & reinstall WhatsApp and restore from backup.
Limitation: You’ll lose any messages received after the backup.
Third-Party Apps
Some apps claim to recover deleted messages, but they require notification access or file access.
Risk: Many of these apps can compromise your privacy or security. Always be careful with what permissions you give.
Forwarded Media
If the deleted message was a photo, video, or file, it may still remain in your phone’s gallery or WhatsApp media folder even after deletion.
iPhone users generally cannot see deleted messages unless they restore an old iCloud backup.
No method works if the message never appeared in your notifications or backups.
Be cautious of shady apps or websites that claim they can "magically" recover deleted WhatsApp chats — most are scams.