In one-on-one chats, either person can choose to enable or disable disappearing messages. In group chats, admins will have control.
How to enable and disable disappearing messages in Android, iOS and web
Open WhatsApp and head to any chat window
Tap on contact’s name
Then, tap on disappearing messages option
Tap Continue, if prompted
Now, select On to turn on disappearing messages for that particular chat.
Head back to the chat window and you will find a new disappearing messages logo on the profile picture.
To turn off disappearing messages, head back to that chat window, tap on contact’s name and select Off under the disappearing messages option.
How to enable and disable disappearing messages on KaiOS (JioPhone)
Open any WhatsApp chat
Press Options -> View Contact -> OK.
Choose disappearing Messages and head to Edit option
If prompted, press Next
Select On and press the Ok button
To turn off, Select Off and press the Ok button