How to activate the Vanish Mode feature on Messenger-hidden messages.... 

Vanish Mode

For its part, “business insider” explained that if a user takes a screenshot of the Vanish Mode chat, both users will be alerted, especially as this feature erases the message as soon as it is read.

Steps to activate hidden messages in Messenger

You can now use the Vanish Mode feature after installing the Messenger app on iPhone or Android phones, by following a number of simple and easy steps as follows:

First: You must initially open the Messenger app or chat with someone, and here the conversation must be individual, especially since this feature and Vanish Mode do not work in group chats.

Second: The user has to swipe up from the bottom of the screen, and you should see a message telling you to swipe up to get to Vanish Mode, and keep swiping until the circle icon is completely filled.

Third: Your current conversations will disappear and will be replaced by a blank Vanish Mode screen, and if it is the first time you activate this feature, you will get a popup with a number of information about that wonderful mode.

Fourth: Through the Vanish Mode screen, the user can send messages or pictures like normal conversations, as they continue until the recipient sees that message and closes the chat.