You will need to get permission from the other party
The new feature, which has been tried in internal tests in the past months, will be made available globally in the coming weeks with its renewed version. With this feature, users will be able to hide the lost messages from the other party. Meta has strengthened this feature with privacy and security measures after internal trials.
If you want to save a disappearing message with the renewed feature, you can ask the other person “Someone wants to keep your lost message, do you allow it?” notification will be sent and you will be able to keep this message if the other party gives permission. If the other party does not allow, your transaction will be blocked and the message will disappear after the specified time. Stored messages will appear in the chat with the “bookmark” icon.