Open WhatsApp and check whether the chat is archived
Restore the chat from a recent WhatsApp backup on Google Drive or iCloud
Uninstall WhatsApp
Reinstall WhatsApp
Verify your phone number
Tap Restore when prompted
Restore from a local backup on Android if available
Use a file manager to find the WhatsApp backup folder
Rename the desired backup file to the latest backup filename
Reinstall WhatsApp and restore from the local backup
Check whether the chat was exported to email or another app
Ask the other person to resend the messages
Use a third-party recovery tool only if you trust it and understand the risks
Enable automatic backups to prevent future loss