You must note that this isn’t a message and you will need to download a third-party app from Google Play store. Another thing to note is, the app that can let you read deleted messages is available only for Android users and not for iPhone users. Here’s how you can read deleted WhatsApp messages:
To start with download WhatsRemoved app from Google Play store on the same phone in which you have the WhatsApp account.
Open the app and set it up first and accept all terms and conditions. The app contains lots of advertisements.
The app support many platforms including WhatsApp. To read deleted messages on WhatsApp select the app from the list and then click on continue.
The WhatsRemoved+ app will then ask you whether it should save files or not and then take to a page that will show all deleted WhatsApp messages. Just click on WhatsApp option next to the Detected option on top of the screen.
Enable the setting and you will be able to read all deleted WhatsApp messages.
These are third-party apps and all users must be careful using them.